At our next women's gathering for church we are making natural stone coaster sets. I found 9 packs of 4X4 tiles at Home Depot for 3.97 I think. I am sure Lowes probably has them too. I have done some reading on these and I think everybody agrees that if you are going to stamp designs on them use StazOn ink pads. This is a permanent quick drying, waterproof ink. The colors are very vivid. I only have a blue and green so far. They are really dark. You can use other inks (I used Memento dewdrops)if you are going to seal these coasters with a clear coat. If you spray them with clear coat, they lose their natural absorbent quality. I also have some Black India Ink that is waterproof and permanent that I used to outline several items and write a few words. I don't think I like any of these! I am definitely glad I am practicing at home first. I want to give sets of four to relatives at Christmas. It really isn't that expensive to do, so I want to find 4 designs that go together and look nice enough to present as gifts. I guess all these bad ones will hang out at my house for personal use. I also bought some clearance pressed flowers at Michaels that I think I might try to decoupage on some and then seal with clear coat. It is fun trying, but I wish I had better results!!!!