UNIKAT is Polish for unique and this word is stamped on the bottom of each piece of the higher end Polish Stoneware patterns. The most elite of Zaklady Ceramiczne "BOLESLAWIEC' paint the UNIKAT patterns. This category of patterns are also known as the Signature Series. Master artisans like Iwona Piela & Andrzej Pachom employ sponges as in the century old technique known as hand stamp but also brushes to add depth and additional character to each vessel. After they are done painting the UNIKAT pattern, they lovingly sign the bottom of each and use a rubber stamp to brand it UNIKAT. Each dinner plate, saucer and cereal bowl is truly a UNIKAT (unique) and will become a treasured heirloom as family tables are set and you experience the elegance of eating off Polish Pottery. You can also be confident your dinnerware will not chip or break from normal everyday use. This dinnerware is certified to go into the oven up to 480 degrees, microwave, dishwasher, refrigerator, freezer safe. To ensure longevity, avoid drastic temperature swings or placing to close to a heat source as in broiling.