{"product_id":"col-o-ring-ink-testing-book","title":"Col-o-ring Ink Testing Book","description":"\u003cp class=\"p1\"\u003e\u003cb\u003eThe Serious Collector's Standard\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eCol-o-ring was created specifically to solve a cataloguing problem the fountain pen community ran into when a previously favoured Japanese flashcard product was discontinued. The result, developed with a paper specialist, uses 160gsm acid-free European paper rigorously tested to resist feathering, bleeding, and show-through — performance that matters when judging an ink's true sheen and shading characteristics. The split-ring binding is the other key feature: individual cards can be removed, reordered by colour family or brand, or added to indefinitely, rather than being fixed in book order. Reviewers with very large ink collections (some maintain 400+ swatch cards) confirm this remains practical at scale when paired with binder sleeve pages.\u003c\/p\u003e","brand":"Col-o-ring","offers":[{"title":"Default Title","offer_id":53365929804104,"sku":null,"price":0.0,"currency_code":"GBP","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0935\/0709\/2808\/files\/Col-o-ringInkTestingBook.png?v=1782304029","url":"https:\/\/inkwellartsupplies.com\/products\/col-o-ring-ink-testing-book","provider":"Inkwell Art Supplies","version":"1.0","type":"link"}