These are PVC (polyvinylchloride) with additions such as plasticizers to give flexibility, pigments for colour, and other chemicals to provide specific qualities such as improved resistance to UV radiation and temperature fluctuations. Solvents are also used in the manufacture of cast films.

Cast films are made by a liquid mixture of the ingredients being poured on to a moving web (called a casting sheet) and put through one or more ovens to evaporate the solvents.

Casting produces a thin film with particularly good conformity and dimensional stability that holds its shape very well. Ideal for application over rivets, welds, complex curves and other irregularities, vehicle wrapping is the most popular application for cast vinyl. A good wrap with the correct printed vinyl can look like, and perform like, paint. Cast vinyl is available in a very wide range of colours and the way it's manufactured means it's practical to produce relatively small quantities of special colours. Casting usually produces films with the highest gloss and the longest outdoor durability.

Calendered films are produced by a thicker mixture being fed through a series of rollers, known as calendars, which progressively squeeze it down to the thickness of film required. Films made with polymeric plasticizers are usually higher quality with greater conformity than those made with monomeric plasticizers.

Because they are squashed and stretched to their finished shape, calendered vinyls are less dimensionally stable and when heated; they tend to contract and change shape back towards their original form. The manufacturing process for calendered films also limits how thin they can be, although this gives an advantage in that thicker or stiffer vinyl can make for easier handling with improved resistance to abrasion. The choice of colour in calendered films is more limited and their production method means producing special colours isn't as easy or economical.

But the biggest advantage of calendered films that they cost considerably less than cast films, largely because they're produced in bulk. Calendered films are a perfect solution for flat and simply curved surfaces, such as point of sale displays, wall, window and floor graphics, and for applications not requiring such long term outdoor durability of many years.

Dispite their greater cost cast vinyls may have an edge over calendered films but the development in calendered films over recent years is very exciting. Manufacturers are creating increasingly thin calendered films, with improved conformability and dimensional stability, as well as longer outdoor durability.