{"product_id":"ultrox-zirconium-glaze-opacifier-rmultzir","title":"Ultrox: Zirconium Glaze Opacifier","description":"\u003cp\u003e\u003cstrong\u003eA zircon opacifier for bright, clean whites at a fraction of the cost of tin. Use it wherever a recipe lists Zircopax.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv class=\"rm-testing-statement\" style=\"border:2px solid #8a5a00;border-radius:6px;padding:12px 16px;margin:16px 0;background:#fdf6e3;\"\u003e\u003cp style=\"margin:0;\"\u003e\u003cstrong\u003eYou must test before you use it, at any scale.\u003c\/strong\u003e Raw materials, mined or man-made, are not consistent. Color, strength, particle size and chemistry can change from one bag to the next and from one supplier to another, even when the name on the bag stays the same. Before you use this material in a glaze, slip or clay body of any size, mix a small test batch, fire it on your own clay in your own kiln, and check the results.\u003c\/p\u003e\u003c\/div\u003e\n\u003ch3\u003eWhat it is\u003c\/h3\u003e\n\u003cp\u003eAn opacifier: a white powder (zirconium silicate) that turns a clear glaze into an opaque white. Zircon whites are brighter and cooler than tin whites and cost much less. Ultrox is made to substitute for Zircopax in your recipes without other changes, but test it first.\u003c\/p\u003e\n\u003ch3\u003eGetting started\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eFor an opaque white, start at 8 to 10% (8 to 10 grams per 100 grams of dry glaze). Many glazes use up to 15%.\u003c\/li\u003e\n\u003cli\u003eIf your recipe lists Zircopax, Superpax or \"zircon,\" use Ultrox in the same amount, then fire a test tile.\u003c\/li\u003e\n\u003cli\u003eIt also whitens slips and engobes and softens colors toward pastels.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFor glaze formulators\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eZirconium silicate, ZrSiO₄.\u003c\/li\u003e\n\u003cli\u003eStiffens the melt at higher amounts and can push glossy glazes toward satin.\u003c\/li\u003e\n\u003cli\u003eLowers glaze thermal expansion, which can help reduce crazing.\u003c\/li\u003e\n\u003cli\u003eStable with most colorants. Unlike tin, it doesn't turn pink with chrome.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSafety\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eLow toxicity, but don't breathe the dust. Wear a NIOSH-approved respirator (N95 or better) when handling it dry, and clean up with a wet sponge, not a broom.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSizes \u0026amp; pricing\u003c\/h3\u003e\n\u003ctable style=\"width:100%;max-width:520px;border-collapse:collapse;border:0;margin:0 0 14px;font-variant-numeric:tabular-nums;line-height:1.35;\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"padding:0 0 6px;border:0;border-bottom:2px solid #d9d0c4;background:transparent;font-size:12px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#6b6259;text-align:left;width:40%;\"\u003eSize\u003c\/th\u003e\n\u003cth style=\"padding:0 0 6px;border:0;border-bottom:2px solid #d9d0c4;background:transparent;font-size:12px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#6b6259;text-align:right;padding-left:12px;\"\u003ePrice\u003c\/th\u003e\n\u003cth style=\"padding:0 0 6px;border:0;border-bottom:2px solid #d9d0c4;background:transparent;font-size:12px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#6b6259;text-align:right;padding-left:12px;\"\u003ePer lb\u003c\/th\u003e\n\u003cth style=\"padding:0 0 6px;border:0;border-bottom:2px solid #d9d0c4;background:transparent;font-size:12px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#6b6259;text-align:right;padding-left:12px;\"\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e1 lb\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$5.15\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$5.15\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e\u003ca href=\"\/cart\/add?id=45113758384450\u0026amp;quantity=1\" style=\"color:#2340a8;font-weight:600;font-size:13px;text-decoration:none;white-space:nowrap;\"\u003eAdd to cart\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e5 lb\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$25.00\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$5.00\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e\u003ca href=\"\/cart\/add?id=67286165586291\u0026amp;quantity=1\" style=\"color:#2340a8;font-weight:600;font-size:13px;text-decoration:none;white-space:nowrap;\"\u003eAdd to cart\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e10 lb\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$49.00\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$4.90\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e\u003ca href=\"\/cart\/add?id=67286165619059\u0026amp;quantity=1\" style=\"color:#2340a8;font-weight:600;font-size:13px;text-decoration:none;white-space:nowrap;\"\u003eAdd to cart\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e25 lb\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$120.00\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$4.80\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e\u003ca href=\"\/cart\/add?id=67286165651827\u0026amp;quantity=1\" style=\"color:#2340a8;font-weight:600;font-size:13px;text-decoration:none;white-space:nowrap;\"\u003eAdd to cart\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;font-weight:700;\"\u003e55 lb bag\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;font-weight:700;\"\u003e$247.50\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;font-weight:700;\"\u003e$4.50\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e\u003ca href=\"\/cart\/add?id=67286165684595\u0026amp;quantity=1\" style=\"color:#2340a8;font-weight:600;font-size:13px;text-decoration:none;white-space:nowrap;\"\u003eAdd to cart\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cdiv style=\"max-width:520px;margin:0 0 12px;padding:12px 14px;border-radius:8px;background:#eef3ee;border:1px solid #d6e3d7;\"\u003e\n\u003cp style=\"margin:0 0 10px;\"\u003e\u003cstrong\u003eFull bags mix and match.\u003c\/strong\u003e Every full bag in your order, of any raw material, adds up. That total sets the price of every bag. Smaller sizes don't count.\u003c\/p\u003e\n\u003ctable style=\"width:100%;max-width:520px;border-collapse:collapse;border:0;margin:0;font-variant-numeric:tabular-nums;line-height:1.35;\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"padding:0 0 6px;border:0;border-bottom:2px solid #d9d0c4;background:transparent;font-size:12px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#6b6259;text-align:left;width:46%;\"\u003eFull bags in your order\u003c\/th\u003e\n\u003cth style=\"padding:0 0 6px;border:0;border-bottom:2px solid #d9d0c4;background:transparent;font-size:12px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#6b6259;text-align:right;padding-left:12px;\"\u003ePrice per 55 lb bag\u003c\/th\u003e\n\u003cth style=\"padding:0 0 6px;border:0;border-bottom:2px solid #d9d0c4;background:transparent;font-size:12px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#6b6259;text-align:right;padding-left:12px;\"\u003ePer lb\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003eUnder 500 lb\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$247.50\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$4.50\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e500 lb and up\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$243.00\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$4.42\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e2,000 lb and up\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$238.00\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$4.33\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e6,000 lb and up\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$233.00\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$4.24\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e12,000 lb and up\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$228.00\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$4.15\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp style=\"margin:0;font-size:13px;color:#6b6259;\"\u003ePrices from our October 23, 2026 price list.\u003c\/p\u003e","brand":"Sheffield Pottery","offers":[{"title":"1 Pound","offer_id":45113758384450,"sku":"RMULTZIR","price":5.15,"currency_code":"USD","in_stock":true},{"title":"5 Pounds","offer_id":67286165586291,"sku":"RMULTZIR-5","price":25.0,"currency_code":"USD","in_stock":true},{"title":"10 Pounds","offer_id":67286165619059,"sku":"RMULTZIR-10","price":49.0,"currency_code":"USD","in_stock":true},{"title":"25 Pounds","offer_id":67286165651827,"sku":"RMULTZIR-25","price":120.0,"currency_code":"USD","in_stock":true},{"title":"55 Pounds","offer_id":67286165684595,"sku":"RMULTZIR50","price":247.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0677\/5508\/2050\/files\/large-Ziropax_powder_1_5f0fef53-8b76-415e-9cec-ab5d075d8ef1.jpg?v=1791876724","url":"https:\/\/www.sheffield-pottery.live\/products\/ultrox-zirconium-glaze-opacifier-rmultzir","provider":"Sheffield Pottery Inc.","version":"1.0","type":"link"}