{"title":"TWSBI","description":"","products":[{"product_id":"twsbi-eco-fountain-pen-white","title":"TWSBI Eco Fountain Pen - White","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cspan\u003eA demonstrator-style piston filler with a clear acrylic barrel and a solid white hexagonal cap. TWSBI's entry-level model, widely credited with bringing piston-filling into reach at this price point. Made for the beginner who just wants to try out fountain pens, all the way to the experts. A good everyday worker.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eWhy It's Special\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003ePiston-filling mechanism at an entry-level price — most pens this affordable use cartridges or converters\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eHigh ink capacity, roughly 1.7 ml — several times what a standard converter holds\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eClear barrel lets you see ink level and color\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFully user-serviceable; ships with a wrench and silicone grease for disassembly and maintenance\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGerman-made stainless steel nib\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eType: Fountain pen, medium nib\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMaterial: Clear acrylic barrel, white resin cap and piston knob\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eTrim: Chrome\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFilling: Piston\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInk capacity: ~1.7 ml\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCap: Hexagonal, screw-on, postable\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCapped length: 138.4 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003ePosted length: 167.6 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eBody diameter: 12.7 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eWeight: ~21 g\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003ePlease note: TWSBI products are not eligible for discounts.\u003c\/em\u003e\u003c\/p\u003e","brand":"TWSBI","offers":[{"title":"Extra Fine","offer_id":47859634372773,"sku":"TSB-M7444330","price":36.99,"currency_code":"USD","in_stock":true},{"title":"Fine","offer_id":47859566182565,"sku":"TSB-M7444340","price":36.99,"currency_code":"USD","in_stock":false},{"title":"Medium","offer_id":47859566215333,"sku":"TSB-M7444350","price":36.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/6046\/2501\/files\/TWSBIEcoFountainPen-White-PistonFiller-Demonstrator-MadeinTaiwan_4.jpg?v=1779925302"},{"product_id":"twsbi-eco-fountain-pen-black","title":"TWSBI Eco Fountain Pen - Black","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cspan\u003eA demonstrator-style piston filler with a clear acrylic barrel and a solid black hexagonal cap. TWSBI's entry-level model, widely credited with bringing piston-filling into reach at this price point. Made for the beginner who just wants to try out fountain pens, all the way to the experts. A good everyday worker.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eWhy It's Special\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003ePiston-filling mechanism at an entry-level price — most pens this affordable use cartridges or converters\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eHigh ink capacity, roughly 1.7 ml — several times what a standard converter holds\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eClear barrel lets you see ink level and color\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFully user-serviceable; ships with a wrench and silicone grease for disassembly and maintenance\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGerman-made stainless steel nib\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eType: Fountain pen, medium nib\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMaterial: Clear acrylic barrel, black resin cap and piston knob\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eTrim: Chrome\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFilling: Piston\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInk capacity: ~1.7 ml\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCap: Hexagonal, screw-on, postable\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCapped length: 138.4 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003ePosted length: 167.6 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eBody diameter: 12.7 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eWeight: ~21 g\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003ePlease note: TWSBI products are not eligible for discounts.\u003c\/em\u003e\u003c\/p\u003e","brand":"TWSBI","offers":[{"title":"Extra Fine","offer_id":47859727827109,"sku":"TSB-M7444280","price":36.99,"currency_code":"USD","in_stock":true},{"title":"Fine","offer_id":47859727859877,"sku":"TSB-M7444290","price":36.99,"currency_code":"USD","in_stock":true},{"title":"Medium","offer_id":47859727892645,"sku":"TSB-M7444300","price":36.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/6046\/2501\/files\/TWSBIEcoFountainPen-Black-PistonFiller-Demonstrator-MadeinTaiwan_1_webp.jpg?v=1779925322"},{"product_id":"twsbi-eco-fountain-pen-clear","title":"TWSBI Eco Fountain Pen - Clear","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cspan\u003eA demonstrator-style piston filler with a clear acrylic barrel and hexagonal cap. TWSBI's entry-level model, widely credited with bringing piston-filling into reach at this price point. Made for the beginner who just wants to try out fountain pens, all the way to the experts. A good everyday worker.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eWhy It's Special\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003ePiston-filling mechanism at an entry-level price — most pens this affordable use cartridges or converters\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eHigh ink capacity, roughly 1.7 ml — several times what a standard converter holds\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eClear barrel lets you see ink level and color\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFully user-serviceable; ships with a wrench and silicone grease for disassembly and maintenance\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGerman-made stainless steel nib\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eType: Fountain pen, medium nib\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMaterial: Clear acrylic barrel, clear resin cap and piston knob\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eTrim: Chrome\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFilling: Piston\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInk capacity: ~1.7 ml\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCap: Hexagonal, screw-on, postable\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCapped length: 138.4 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003ePosted length: 167.6 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eBody diameter: 12.7 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eWeight: ~21 g\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003ePlease note: TWSBI Products are not eligible for discounts.\u003c\/em\u003e\u003c\/p\u003e","brand":"TWSBI","offers":[{"title":"Extra Fine","offer_id":47859976241317,"sku":"TSB-M7445300","price":36.99,"currency_code":"USD","in_stock":true},{"title":"Fine","offer_id":47859976274085,"sku":"TSB-M7445310","price":36.99,"currency_code":"USD","in_stock":true},{"title":"Medium","offer_id":47859976306853,"sku":"TSB-M7445320","price":36.99,"currency_code":"USD","in_stock":true},{"title":"Stub 1.1 mm","offer_id":47859977060517,"sku":"TSB-M7445340","price":36.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/6046\/2501\/files\/TWSBIEcoFountainPen-Clear-PistonFiller-Demonstrator-MadeinTaiwan_1_webp.jpg?v=1779925345"},{"product_id":"twsbi-eco-fountain-pen-carrara-w-onyx","title":"TWSBI Eco Fountain Pen - Carrara w\/ Onyx","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cspan\u003eA demonstrator-style piston filler with a clear acrylic barrel and Carrara marble-like swirled hexagonal cap. TWSBI's entry-level model, widely credited with bringing piston-filling into reach at this price point. Made for the beginner who just wants to try out fountain pens, all the way to the experts. A good everyday worker.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eWhy It's Special\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003ePiston-filling mechanism at an entry-level price — most pens this affordable use cartridges or converters\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eHigh ink capacity, roughly 1.7 ml — several times what a standard converter holds\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eClear barrel lets you see ink level and color\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFully user-serviceable; ships with a wrench and silicone grease for disassembly and maintenance\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGerman-made stainless steel nib\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eType: Fountain pen, medium nib\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMaterial: Clear acrylic barrel, Carrera marble-like resin cap and piston knob\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eTrim: Black metal trim\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFilling: Piston\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInk capacity: ~1.7 ml\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCap: Hexagonal, screw-on, postable\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCapped length: 138.4 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003ePosted length: 167.6 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eBody diameter: 12.7 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eWeight: ~21 g\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003ePlease note: TWSBI Products are not eligible for discounts.\u003c\/em\u003e\u003c\/p\u003e","brand":"TWSBI","offers":[{"title":"Fine","offer_id":47859980402853,"sku":"TSB-M7442740","price":58.99,"currency_code":"USD","in_stock":true},{"title":"Medium","offer_id":47859980435621,"sku":"TSB-M7442750","price":58.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/6046\/2501\/files\/ECO-Carrara-02.webp?v=1779925571"},{"product_id":"twsbi-diamond-580alr-fountain-pen-black","title":"TWSBI Diamond 580ALR Fountain Pen - Black","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cspan\u003eTWSBI's flagship demonstrator, with a faceted clear acrylic barrel and matte black anodized aluminum hardware. The \"ALR\" designation refers to the aluminum grip and piston mechanism, finished with subtle circular engravings on the grip and cap finial for tactile texture.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cspan\u003eAccessories with \u003ca href=\"https:\/\/thepapermind.com\/products\/twsbi-diamond-580-fountain-pen-replacement-nib-set\"\u003espare 580 nibs\u003c\/a\u003e and a \u003ca href=\"https:\/\/thepapermind.com\/products\/twsbi-diamond-50-ink-bottle-50-ml-polished-aluminum\"\u003ematching inkwell\u003c\/a\u003e specially designed for the Diamond 580.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eWhy It's Special\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFaceted \"diamond-cut\" barrel that refracts light through the ink and keeps the pen from rolling\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eHigher ink capacity than the ECO — roughly 1.95 ml via the piston filler\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMachined aluminum grip section, connector, and piston rod (the ECO is all resin)\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eEngraved tactile grooves on grip and cap finial for slip resistance\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFully user-serviceable; ships with a wrench and silicone grease for disassembly and maintenance\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGerman-made stainless steel nib\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eType: Fountain pen, fine nib\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMaterial: Clear acrylic barrel, matte black anodized aluminum section and trim\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFilling: Piston\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInk capacity: ~1.95 ml\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCap: Screw closure (posting not recommended — the cap engages the piston when twisted on the back)\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eClip: Spring metal\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCapped length: 142.2 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eBody length: 130.2 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eBody diameter: 12.7 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eWeight: 26.9 g\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003ePlease note: TWSBI products are not eligible for discounts.\u003c\/em\u003e\u003c\/p\u003e","brand":"TWSBI","offers":[{"title":"Extra Fine","offer_id":47860019691685,"sku":"TSB-M7440940","price":72.99,"currency_code":"USD","in_stock":true},{"title":"Fine","offer_id":47860019724453,"sku":"TSB-M7440950","price":72.99,"currency_code":"USD","in_stock":true},{"title":"Medium","offer_id":47860019757221,"sku":"TSB-M7440960","price":72.99,"currency_code":"USD","in_stock":true},{"title":"Stub 1.1 mm","offer_id":47860021821605,"sku":"TSB-M7440980","price":72.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/6046\/2501\/files\/Diamond_580ALR_Black01.webp?v=1779925403"},{"product_id":"twsbi-diamond-580-fountain-pen-clear","title":"TWSBI Diamond 580 Fountain Pen - Clear","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cspan\u003eTWSBI Diamond 580, a classic fountain pen with a piston ink-filling system. By fusing the traditional mechanisms of the fountain pen with a modern industrial design, we have created an eye-catching fountain pen that is simultaneously appreciative of the past and relevant in the present. The Diamond 580 comes with a benchmark ink-filling mechanism and has all detachable parts. We felt that it was important to allow the user to disassemble and reassemble the pen and completely experience the traditional aspects of owning and using a fountain pen.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cspan\u003eAccessories with \u003ca href=\"https:\/\/thepapermind.com\/products\/twsbi-diamond-580-fountain-pen-replacement-nib-set\"\u003espare 580 nibs\u003c\/a\u003e and a \u003ca href=\"https:\/\/thepapermind.com\/products\/twsbi-diamond-50-ink-bottle-50-ml-polished-aluminum\"\u003ematching inkwell\u003c\/a\u003e specially designed for the Diamond 580.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eWhy It's Special\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFully transparent throughout — the clear grip section lets you watch ink move through the feed\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFaceted \"diamond-cut\" barrel that refracts light through the ink and keeps the pen from rolling\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eHigh ink capacity, roughly 1.95 ml via piston filler\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eChrome-plated trim and spring-metal clip\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFully user-serviceable; ships with a wrench and silicone grease for disassembly and maintenance\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGerman-made stainless steel nib\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eType: Fountain pen, fine nib\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMaterial: Clear acrylic body and section\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eTrim: Chrome-plated\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFilling: Piston\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInk capacity: ~1.95 ml\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCap: Screw closure (posting not recommended — the cap engages the piston when twisted on the back)\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eClip: Spring metal\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCapped length: 142.2 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eBody length: 130 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eBody diameter: 13.2 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGrip diameter: 10.2 mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eWeight: ~28 g\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003ePlease note: TWSBI products are not eligible for discounts.\u003c\/em\u003e\u003c\/p\u003e","brand":"TWSBI","offers":[{"title":"Broad","offer_id":47860025819301,"sku":"TSB-7443140","price":55.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/6046\/2501\/files\/TWSBI_Diamond_580_Fountain_Pen_-_Clear_-_Piston_Filler_-_Demonstrator_-_Made_in_Taiwan.jpg?v=1779925772"},{"product_id":"twsbi-diamond-580-fountain-pen-replacement-nib-set","title":"TWSBI Diamond 580 Fountain Pen Replacement Nib Set","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cmeta charset=\"UTF-8\"\u003e\u003cspan\u003eStainless steel replacement nib unit for the \u003ca href=\"https:\/\/thepapermind.com\/products\/twsbi-diamond-580-fountain-pen-clear\"\u003eTWSBI 580\u003c\/a\u003e, 580AL, and \u003ca href=\"https:\/\/thepapermind.com\/products\/twsbi-diamond-580alr-fountain-pen-black\"\u003e580ALR\u003c\/a\u003e (will also fit 530 and 540). Includes the nib, feed, housing, and clear plastic grip section — a full unit swap rather than just a nib.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eNib: Stainless Steel TWSBI branded JoWo #5\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eIncludes: Nib, feed, housing, clear grip section\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e\u003cspan\u003eCompatible with: \u003ca href=\"https:\/\/thepapermind.com\/products\/twsbi-diamond-580-fountain-pen-clear\"\u003eTWSBI Diamond 580\u003c\/a\u003e, 580AL, \u003ca href=\"https:\/\/thepapermind.com\/products\/twsbi-diamond-580alr-fountain-pen-black\"\u003e580ALR\u003c\/a\u003e (also Diamond 540 and 530)\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003ePlease note: TWSBI products are not eligible for discounts.\u003c\/em\u003e\u003c\/p\u003e","brand":"TWSBI","offers":[{"title":"Extra Fine","offer_id":47860036206757,"sku":"TSB-7443560","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Fine","offer_id":47860036239525,"sku":"TSB-7443570","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Medium","offer_id":47860036272293,"sku":"TSB-7443580","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Broad","offer_id":47860029391013,"sku":"TSB-7443590","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Stub 1.1 mm","offer_id":47860036305061,"sku":"TSB-7443600","price":22.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/6046\/2501\/files\/Diamond-580-nib-set-F_e188bc9b-82ba-42df-bbe6-dc4066d5d259.webp?v=1779925458"},{"product_id":"twsbi-diamond-50-ink-bottle-50-ml-polished-aluminum","title":"TWSBI Diamond 50 Ink Bottle - 50 ml - Polished Aluminum","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eTWSBI Diamond 50 Ink Bottle — Polished Aluminum (50 ml)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003eA faceted glass inkwell with a polished anodized aluminum cap. The polished aluminum version is the upgraded finish on the standard Diamond 50 bottle, which otherwise ships with a black plastic top. Works with any bottled fountain pen ink and any pen, with extra functionality for TWSBI's piston-filler line.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eWhat makes it special\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eTwo-part cap: the lower section unscrews for normal bottle filling; the upper section threads directly onto \u003ca href=\"https:\/\/thepapermind.com\/products\/twsbi-diamond-580alr-fountain-pen-black\"\u003eTWSBI Diamond\u003c\/a\u003e, Classic, and Mini sections so you can fill the pen without dipping the nib\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInternal removable reservoir — flip the bottle (cap on) to load a metered amount of ink, useful when the bottle runs low\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003ePolished anodized aluminum cap upgrade over the standard black plastic version\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eAdapter also fits standard international converters\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eSpecs\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCapacity: 50 ml\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMaterial: Glass body, anodized aluminum cap\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFinish: Polished\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eTWSBI pen compatibility: \u003ca href=\"https:\/\/thepapermind.com\/products\/twsbi-diamond-580-fountain-pen-clear\"\u003eDiamond 580\u003c\/a\u003e \/ 580AL \/ \u003ca href=\"https:\/\/thepapermind.com\/products\/twsbi-diamond-580alr-fountain-pen-black\"\u003e580ALR\u003c\/a\u003e \/ 540 \/ 530, Classic, Mini\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGeneral compatibility: Any fountain pen ink, any bottle-fill pen (with the adapter removed)\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInk: Not included\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003ePlease note: TWSBI products are not eligible for discounts.\u003c\/em\u003e\u003c\/p\u003e","brand":"TWSBI","offers":[{"title":"Default Title","offer_id":47860053180581,"sku":"TSB-M7447690","price":34.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/6046\/2501\/files\/TWSBI_Diamond_50_Ink_Bottle_-_50_ml_-_Polished_Aluminum.webp?v=1779925258"},{"product_id":"twsbi-pipe-pen-filler-for-refilling-twsbi-fountain-pens","title":"TWSBI Pipe Pen Filler For Refilling Converters and TWSBI Fountain Pens","description":"\u003cp\u003e\u003cspan\u003eA 4-inch stainless steel snorkel that extends the reach of a fountain pen or converter into deep, narrow, or nearly empty ink bottles. Attaches directly to compatible pen barrels and converters; the pen's own piston or the converter's mechanism does the drawing.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy it's special:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eReaches the bottom of tall, narrow, or low-fill bottles where the pen body won't fit — including sample vials\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eActs as a direct extension of the pen: the grip section comes off and the pipe threads on in its place\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eStainless steel throughout, no plastic in the ink path\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFits the TWSBI Diamond 580 line, Mini, Classic, and Precision, plus most standard international converters and TWSBI's own Spring-Loaded and Piston converters used in the SWIPE\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eShips with protective end caps to discard before first use\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eSpecs: \u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMaterial: Stainless steel\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eLength: 4 in (10 cm)\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCompatible with: TWSBI Diamond 580 \/ 580AL \/ 580ALR \/ Mini, Classic, Precision; most standard international converters; TWSBI Spring-Loaded and Piston converters\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"TWSBI","offers":[{"title":"Default Title","offer_id":47860063830181,"sku":"TSB-M7448250","price":11.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/6046\/2501\/files\/TWSBI_Pipe_Pen_Filler_For_Refilling_Converters_and_TWSBI_Fountain_Pens.webp?v=1779926247"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/6046\/2501\/collections\/DSC07316.webp?v=1779979575","url":"https:\/\/thepapermind.com\/collections\/twsbi.oembed","provider":"The Paper Mind","version":"1.0","type":"link"}