Process that uses cyan, magenta, yellow and black to create multiple colors using only four screens. The example to the left has an additional spot white . The inks are transparent, so four color process printing only works on white or natural colored garments. It is a labor intensive process, so the minimum number of shirts is 72 with the same design, but it is more cost effective than printing multiple spot colors. Exact PMS color matches are not available, but reference colors like corporate colors that must be exact can be added as an additional spot color screen if necessary.
Spot Color Printing
The term Spot Color is where each individual color in a design is separated out and printed separately. This is the least expensive form of screen printing, though not everyone does it as well as others. There is a skill required to align each color screens to get a good clean print. The use of dot patterns or "halftones" can provide a lot of shading and depth to a design even though only one or two screens are used.
Index Color Separation T-shirt
Index color is a process where a design with lots of colors is reduced down to a limited number of colors. This process uses dots, similar to what you would do to create a gradient, but instead of using halftone dots, Indexing uses the same size dots but converts the design to a diffusion dither random square dot pixel pattern.
This pattern allows us to get a cleaner print and provides a brighter print with higher contrast. One of the greatest advantages is that you can print this on dark colors as well as light.
The downside to indexed color is that normally to index requires 6 to 8 or more colors to get the image to look good. If the image does not have a lot of colors it can be a great method to really capture detail and sharpness like in the Grayscale image to the left.
Spot Color + White Underlay
In order to print on darker shirts a white underlay is most often needed. A thin layer of white is printed then "flash cured" before the following colors are laid down in sequence. This makes the imprint colors really pop, even on darker or even black colored shirts.
Athletic Type T-shirt Printing
Athletic Type printing usually requires a white underlay on dark colored garments. It is characterized by opaque colors on dark garments with no "bleed through" of the underlaying shirt dyes.