Actually i was gonna use these out door rock type ...ummm....rocks...lol...i dunno , they are kinda like the rocks you would use for land scaping, they are about 3/4 of an inch thick and they are not too heavy, i found them in an old part of our neighborhood - an old hose being torn down and rebuilt - so i asked the guys there if they minded if i took some and they were coolw ith it, the "rocks" are various sizes as in length and width and are far from "even", but i think it would look nice-and give my baby a "natural" like living area... im going to try them out and see how i like it, but i also plan on putting some small pebbles on the back of the VIV for extra looks, you know like the rocks on the sides of out door ashtrays? i figure that i could glue them on to the wood and it would give the VIV a lil more natural look, bu tthis is just an idea as of right now - havent really gotten to look in to it, yet...