OK, this topic has been discussed several times in the past, but I'm having trouble getting decent results with washes. I've tried enamels, acrylics, oils, and inks, over gloss and flat finishes. I'm currently using Windsor & Newton artists' Paynes grey, thinned with Testors brush cleaner (I've tried synthetic turpentine, too), over Glosscote. If I put it on heavy, I get a patchy-looking mess. If I go light, I don't get enough pigment in the crevices to effectively darken anything. Usually, the effect looks good when I first apply the wash, but when it dries, it goes bad (either patchy or invisible). Anyone got any ideas what I'm doing wrong? Thanks.
Dave