I have used Testos paint thinners and Floquil thinner for years, and never had a problem with my paint projects. In the last year or so Floquil thinner vanished unless all you wanted was a 1 once bottle, many people told me to use Laquer Thinner so I tried it. Every thing I paint fuzzed on the surface, I tired retarder changing the air pressure, adding more volume to the point I was almost spraying pure paint, nothing worked. Yesterday walking through Hobby Bench I spotted this red can of thinner from Testors "Universal Enamal Thinner" for Aztek, Model Master and Floquil brand paints. Oh happy day I don't have to throw out my 30 bottles of Floquil paints. But boy are they proud of this formula at almost 10 dollars for 8 fluid ounces, but my paint flows smoothly again and no more sanding after each application.