Tin chloride coating to sensitize silver deposits ,silver nitrate for silver coating and copper paint for protection to the silver deposits.
Might try Krylon Fusion aerosol paint. Specially designed for plastic. Have used on a Cherokee plastic grill.
acrylic
Normal Paint white works well
The coating on the back of glass that makes it into a mirror used to be silver. Now it is usually aluminum.
you can use what ever kind of paint you want to
Most likely auto enamel paint.
What kind of paint was used? Water or oil based paint?
convex mirrors
because the glass used to make a mirror is green but then covered in a layer of silver therefore when you look down a mirror tunnel it will get dimmer and greener revealing the green glass behind the paint.
Oil
Diego Rivera used to paint frescoes (mural paintings).
A convex mirror is used for:- A spotlight..... the light in right in the middle and the convex mirror is behind it so the light that shines back ward's hits the mirror and reflect's back and bends into a focal point. A concave mirror is used for:- Dentist mirror.... to magnify a potion's teeth. They are also used in car light's but is very hard to explain. The first answer above relates to a concave mirror.