We hand mix and dye our concrete then we swirl and pour that into our coaster molds to create our one of a kind concrete coasters. While we try to stay consistent with our coasters the organic flow of the concrete dictates the designs, no two are alike. We triple seal all our concrete pieces and we use natural cork on the bottom to protect your surfaces. To clean wipe with a damp cloth. These come as sets of 4 in twine in our signature cotton drawstring bag, ready for gift giving. Select from: solid black, black marbled, blue marbled, green marbled, terracotta marbled, dark grey or mixed (all colors except solid black and dark grey) We can also do some custom colors, send us a message if you are interested.