The same questions apply to the powder coating of plastic. Since plastics tend to be non-conductive, the electrostatic charge will not be transferred to ground, and the powder will tend to not stick to the plastic unless it is preheated. The softening point of the plastic will be the constraint on doing this. If it is an engineering plastic, it may take a 300°+ preheat and post heat. If it is a commercial molded product, it probably won't. I spoke with a coater a few days ago who is coating cast pewter parts. The pewter tends to melt at the standard 400° oven temp. Since the part was dense and solid, I guessed that it would not do any flexing after being coated, and the coater could get by on less than a full cure. He will try coating at 275° to 300°. The only down side is poor impact resistance, but he said that should not be a problem.
So, wood and plastic can be coated, but probably not with a standard procedure and cure schedule.
Glass should not be a problem as long as the coater can get the powder on the part. Armstrong Powder Coatings (since purchased by Morton) used to produce a flat black epoxy which was used on a Tequila bottle. One coater I know said he would put a "grounding rod" down the center of glass lamp bases to enhance electrostatic attraction. Others routinely spray hot to get the powder to adhere to the glass, then do a conventional cure. It may take two coats for complete coverage. After the first coat is applied and melted (not cured), it is easier to get the second coat to stick to the first.
Powder Coaters Corner 20
. My hood blow off my Teryx before the last M4SX race going down the raod @ 60MPH & it hardly scratched it. Sorry Tony, Now you must add the Flames to the race car.