Not too long ago, I was working on a decaling project, & I experienced one of those "happy accidents", & ended up with better results than anything I could have planned. So I thought I'd pass it along in case anyone might want to try this one out. Whenever I'm applying decals, the last step, once I've got everything the way I want it, is to apply a flat finish. Sometimes I use Testors Dullcote, but on this occasion, I was applying a sign to the wall of a structure, & I had a bottle of Floquil Flat Finish, with just a tiny amount left in the bottle, & I thought I'd just thin it a bit, & brush it on. So I dipped a brush into a bottle of Diosol (Floquil Thinner) & then into the flat finish. What I didn't realize, until it was too late, was that the Diosol was quite dirty from numerous brush cleanings, & suddenly that nice clean Flat Finish had turned an ugly yellowish brown color...PERFECT...for weathering an old sign! I had used dirty Diosol before for weathering some things, (it's great for staining wood) but I had never dirtied up a bottle of Flat Finish before. I have since used this grimy little mixture on freight cars, & other structures, with great results. Remember, though, as with any weathering technique, subtlty is the key...start very lightly, & build up to the desired result.