When I first came into the motor trade there were basically two ways to paint a car – cellulose or two-pack.
Cellulose paint is a solvent-based paint based on cellulose. It is good but it takes a lot of manual work. Each layer has to be lightly buffed down with wet and dry before a new one is sprayed. And the outcome is very much determined by the skill and attention to detail of the body-shop sprayer. A really good finish has a kind of glass-like finish. A poor quality finish can have a slightly orange peel kind of visual texture. Cellulose was the cheaper option but it was still time-consuming. Then there was two-pack.
Two-pack was always reserved for the really expensive classic car renovations. Two-pack paints include a cyano-acrylate base which sets a bit like superglue. But cyano-acrylates, as the name suggests, are based on cyanide chemicals. So two-pack paint jobs had to be sprayed in a specially ventilated paintshop with the sprayer wearing a fresh-air supplied suit and mask. As you can imagine, that was a lot of kit and a lot of faff. But the results were spectacular. You would get a really perfect finish and one that lasted incredibly well.
More recently the pressure to deliver environmentally-friendly paintshops has meant the industry has shifted over to acrylic, water-based paints. And at the same time the quality of the materials has improved spectacularly. We are able to paint a car better and quicker than previously was possible with cellulose-based paints and really modern acrylic paints are approaching the kind of quality you used to get with the most skilled two-pack sprayers.
And because the time taken to paint the car is shorter the actual cost of labour has come down. Although not every car owner is aware of this and some bodyshops do seem to still exploit this lack of knowledge on the part of customers by over-charging.