Finally finished with my first stone today! I absolutely love how this has come out, and hope to finish the last stone by Christmas so I can mold and cast those two as well.
Casted and painted a new lightweight stone today. Weighing in at only 3.4 oz these would be great for cons and would definitley take a little stress off your bag. This one is rotocast resin with foam innards that provide structural integrity, but keep it light.
I can post measurements in a short while, but as for paints I use the "essential" brand acrylic paints from walmart. Burnt Umber as a base color lightly dusted and dry brushed with Burnt sienna. Do a few light mistings of matte black spray paint to add a little contrast in colors, and speckling like a real rock would typically have, then do the cracks and lines with "titanium white" by Folk Art. Then i seal mine with matte clear spray paint and single coat of testors dull coat.
Ah yes another update on this project. I've finally grown the testicular fortitude to say that these were good enough to stop tweaking, and just mold and begin casting them after 3 years of working on the masters off and on. I found a great resin and filler combo that feels like real stone and also takes paint really well. The first two bigger stones are cast and painted, and I am finishing the mother mold right now for the smallest of the 3 stones so that should be casted and painted in the next few days if all go's right. After 3 years of waiting I can't believe this project is finally reaching the end of the tunnel!