A lot of modern metallic colours now have a "pearl" effect, which shows a greater degree of colour change when viewed from different angles(flip/flop) compared to normal metallics. This is achieved by replacing some, or occasionally all, of the aluminium in the basecoat formula with mica flakes. The mica itself is virtually transparent and acts as microscopic lenses producing a prism effect within the paint.
Normal metallic colours which contain "pearl" are applied in exactly the same way as a standard metallic, but may need extra coats as they can be poor to cover. A coloured groundcoat (undercoat) may also be specified to ensure a uniform appearance.The mica pigments also tend to be expensive, so be prepared to pay more for pearl colours.
Some pearl colours are composed of three distinct layers, firstly a coloured basecoat is applied (not to be confused with a groundcoat). This is followed by a pearl effect basecoat, applied in the usual way, which is then finished with lacquer. This type of system is commonly found on white pearl effect cars, but is becoming more common with other colours
A further variation of these systems can include a tinted (coloured ) lacquer used as the final coatings. Obviously with this type of finish colour variations can be produced by the application of more/less lacquer, as well as the metallic/pearl layers beneath.
