Plastic is a generic term. But if the paint is biting into the plastic, do cross hatch tests if the paint is sticking, then you have taken plastic out of the equation. White enamel ink or paint. If you are planning on printing paint then you would need to contact a paint store to make sure the sprayed and printed paints will work together. Ink which is use for silk screening is still going to have to work with the spray painted paint. This can be a problem because enamels are mostly used as an aggressive ink like on glass and metal. Paint unless it is a two part or better like automotive grade will not stand up the ink. Most enamels are high in solvent content and most paints can not handle the solvent.
Your best bet is to call your ink sales rep and explain what you are doing along with the paint that is sprayed, they are the "experts" and they should be able to identify any problems their ink may have.
Nazdar® 59000 Series Enamel Plus Gloss Screen Ink
59000 Series Enamel Plus Gloss Screen Ink is a solvent-based enamel ink formulated to screen print on a wide range of hard-to-adhere-to surfaces such as glass, metal, wood and some plastics for outdoor signs and displays ...more
Nazdar® 6100 Series Fast Dry Enamel Ink
The 6100 Series Fast Dry Enamel Screen Ink is a solvent-based ink developed for use on flame-treated polyethylene containers, fiber drums and other hard-to-adhere-to surfaces. The 6100 Series has a built-in catalyst that ...more
Nazdar® 8900 Series SuperSet Thermo-Set Screen Ink (Previously SS Series)
8900 Series SuperSet Thermo-Set Screen Ink is a high solids, high gloss solvent-based screen ink. A single component, cross linked product, 8900 Series is formulated for printing on pre-coated metal surfaces. Properly
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These are off of the source one web site and are only from one manufacturer. Always get a MSDS before ordering. I know they are no fun to read but a couple of things to check for are: SARA reportable chemical which you need to file a SARA report to the federal gov along with your local EPA. Also "heavy metal" not music but is the term most often used for inks with lead and mercury in them.
Good Luck