I am planning on adding some decals to some structures. I plan on using styrene as the body of the sign and applying a decal on the styrene. My question is will i need to paint the styrene with clear gloss before applying the decal or not?
Yes, decals will not stick or adhere to bare plastic.
David B
Not to worry. Decals stick to nearly anything. On the other hand, are you not planning to paint the model? Bare styrene has an unrealistic plastic gloss to it. It would look much better with a coat of paint. The model railroading paints Floquil, PollyScale and such will brush on, level out and look good. No airbrush required. Then put the decals on top of the paint.
Conventional wisdom calls for gloss paint under decals, but I have had excellent results decalling over flat and ultra flat (Floquil and Auto Body Primer) paint. Give the decals a shot of Solvaset and they will snuggle right down. Let the decals dry for a day and then give the whole model a shot of Dull Cote. That will make the decal film invisible.