Set of 4, each coaster has a full 3.5" x 3.5" cork backing. Each coaster is 4" x 4". The image is transferred to travertine tile for slight absorbency. The more porous the tile is, the more absorbent it will be. Each one is handmade and unique. Tiles range in color from light to medium dark. By purchasing, you are acknowledging that these coasters are individually made by hand and in no way will be perfect due to the nature of the natural stone, each coaster will be different. They are intended to have that rustic look/feel. These tiles are not always smooth and may be rough on the top, and part of the image missing where there may be holes in the stone. I do my best to position the image where it will show best. These are not dishwasher safe and should be wiped clean with a damp cloth.