How do I paint plastic chairs

clean, spray paint them with Rustoleum 2X for plastic, apply two light coats allowing each to dry in between, seal with a clear UV protectant

Here is a link to a Hometalk who did this. Maybe this post will help you - https://www.hometalk.com/diy/outdoor/furniture/paint-your-plastic-chairs-3821998?r=2

Rustoleum makes spray paint for plastic

clean them very well ,then purchase paint made for plastic and go to work.

There is a certain paint/spray paint that is meant for plastic, you can get t at any hardware/paint store.

Just make sure you do not spray against the wind when using spray paint. And it is better to do a few thin layers rather than one thick layer

Please consider using plastic friendly spray paint -this product does an awesome job.

You may want to decide if you want to satin finish or a gloss finish ( or metallic) both might be available in a wide selection of colors.

A few years ago I spray painted hand-me-down faded mismatched adirondak plastic chairs to make a more cohesive seating and the plastic friendly spray paint worked fine, it was rewarding to rescue and rehab the faded tired chairs.

Rustoleum recommendations

PREPARE:

Always work in a well-ventilated area. Cover the floor and nearby items with a drop cloth. Lightly scuff any glossy surfaces and wipe clean with a lint-free cloth. Use Painter’s tape to hide any surfaces you don’t want to paint.

PAINT:

Using slow, back-and-forth motions, spray paint each item with several light coats of spray paint, making sure to overlap each stroke slightly. Apply 2-3 coats of spray paint, waiting a few minutes in between each coat.

FINISH:

Let spray paint dry for approximately 1 hour before handling.

Tip: Use of 2X Ultra Cover Primer in White provides better paint coverage and color.