For t-shirt printing and other promotional garments and merchandise, screen printing is often employed using one of three different methods. In t-shirt printing, ‘Spot Colour’ printing is the most common and works exceptionally well for a great variety of graphics. Spot color printing is used for those graphics that do not have photographic properties.
The colored ink that is used in reproducing graphic images are chosen by a graphic designer and more often than not are Pantone specified colors. Pantone coated or uncoated colour references are chosen to specify the ink colours of the design. An international colour reference used in publishing, printing and design whereby each colour is identified by a unique Pantone name and number and is called the Pantone matching system.
Branded promotional garments, or other merchandise where color identify and uniformity must stay constant, are particularly well suited for spot color printing.
“4 Colour Process” is another method of t-shirt printing. This is the best way to print photographs and illustrations which contain broad colour ranges, tones, and graduations. Book and magazine images are also printed by the same 4 colour process.
Reproducing the colours of the original image requires a mixing of translucent inks on a white background. It is a lot harder to process on fabric than it is on paper. But the method used is about the same.
This t-shirt printing method only works well on white garments and is unsuitable for coloured fabrics.
The print set up costs are higher than that of simple spot colour designs and as such only suitable for larger print runs of 100+. When t-shirt printers reproduce such full colour images onto coloured fabrics a method called ‘Simulated Process’ is used. Much like spot colour printing, the art is divided into tones and colours to preserve the essential qualities of the original.
Most t-shirt printers use this method, and it is especially popular when used to copy fantasy and heavy metal album artwork onto shirts to be sold by the band. Due to the higher set up prices which includes the separating of the colour as well as an increased amount of colours used to print the pictures, this works out to be the most expensive way of printing.