It's funny, I've never actually used their acrylic clear, but I am surprised it would need to be thinned. I believe they do sell the TS-13 in small bottles, I think it's what's listed as LP-9, but I've only ever used the TS-13 Gloss Clear straight from the can in Tamiya's line. I also really like Testors' Gloss Clear 1261 and Wet Look Clear 1834, also straight from the can, but the first couple of coats over acrylics and craft paints have to be really light.