The origional Floquil RR paints were lacquer based paints origionally designed to be brushed on wood, metal and paper which at that time were used by RR modelers to build engines, rolling stock and structures etc. They were "hot" enough to melt/craze styrene if applied to a kit with a brush (which 99% of the modelers used when styrene kits began to gain popularity). Floquil developed a clear coating to protect the styrene called Barrier which worked but was a real pain to work with (Barrier would cover any fine details) When airbrushes started to become popular, it was found that if you applied a very thin coat of Floguil to a styrene surface, let it dry, and then applied a good color coat, you could get a good paint job. The problems were A. If you applied too much paint on the first coat, it would melt/craze just as if you had applied it with a brush and B. If you tried to remove the paint after application, the etching wouldn't release the paint (ask me how I know that).
Floquil actually started to convert over to an enamel based paint when more and more RR items (again engines, rolling stock and structures etc) began to be produced in styrene (after all, the Model RR folks are Floquils bread and butter).
And Floquils Lacquers have a real nasty smell.