Clean the plastic chair with a damp cloth, use a general-purpose cleaner for hard surfaces to remove any marks and stains.
I allowed it to dry completely in the sun.
Place the chair on a spot sheet in a well-ventilated area and wear a dust mask.
Spray the chair with a thin coat of spray paint. I used Rust-oleum, ultra-cover, paint and primer (also bonds to plastic). Hold the can about 30 cm from the surface of the chair and keep the can moving while you spray. Don’t worry about full coverage during this first coat of paint.
Allow the first coat to dry for about 50 minutes before spraying the second coat. Final inspection: You may have a few spots here and there to touch up.
Let them dry completely for about 5 days before anyone sits on them.