CMYK – Color Separation


CMYK  Separation Tutorial for Screen Printing

This video tutorial shows you how I separate CMYK (Four Color Process) using Adobe Photoshop for t-shirt screen printing. Giving you a trick to obtain halftone value using a simple formula, and then shows you how to put registration mark when printing to film paper.

Selecting Proper Mesh Count in Screen Printing

The mesh size is measured by how many threads there are per square inch. For Example, an 86 mesh screen has 86 threads per square inch. The higher the mesh count, the finer the holes are in the screen allowing finer detail but also reduces the amount of ink you can deposit. The size of the mesh has a lot to do with how thick the ink you are using is. How detailed your image is also a consideration in the mesh count selection.

If you have a design with extremely high detail, a lower mesh screen won't hold the fine lines or dots in the image and they will simply not show up causing a lack of detail in the finished product. On the other hand, if you are trying to print a thicker ink (such as white) through too high of a screen mesh, barely any ink will print through the mesh as the holes are too small. You may notice that different companies have slightly different sizes available. If the mesh count is fairly close, such as 156 vs 160, 196 vs 200, or 81 vs 86, the difference is so small that it doesn't matter because you won't see a significant difference in your final product.

A 110 mesh count is likely the most versatile and used screen mesh in the industry, and for good reason. It yields good detail while remaining quite easy to push most inks through. A 110 mesh count can give likely more detail than most would assume. Unless your detail is very fine, you might try to run a print on a test pellon and examine the results.

There are many variables involved in silk screen printing so we certainly cannot tell you exactly what mesh sizes are used for all applications. However, the following is a general outline of what sizes to use for basic types of printing.
CMYK Angle Cyan 15, Magenta 75, Yellow 0, Black 45 / Note: Water Based Ink, put halftone between 40-45, Solven Based Ink, put halftone between 55 (Manual Press) - 65 (Automatic Press). Halftone Value depending on screen mesh, for example: Halftone Value = 300 (Mesh Count) / 5 = 60 (Divide mesh count value with 4 or 5)
*How to create Base White & CMYK Color Sep in Photoshop for colored T-shirt? Video Tutorial 12, & 3

Note: Mesh counts between 195 and 355 are common, using halftone dot frequencies between 40 and 65 lpi.

To determine the halftone frequency divide the mesh count by 5

Increasing the mesh count can help to reduce moire.
• Underbase – use a 195 mesh with a 45 to 50 lpi halftone.
• Colors – Use 230 to 305 mesh with 50 to 55 lpi.
• Black and Highlight – Use 305 to 355 Mesh with 50 to 65 lpi.

Guidelines for general purpose screen printing  

1. 40-61 mesh count - considered very course mesh counts. They are used for shimmer, glitters and high density inks. Shimmers and glitters have particles in them that will not go through the finer screen meshes.

2. 86 mesh count - considered a course mesh and will provide a heavy ink deposit for high opacity. It is typically used for printing bold copy onto dark colored fabric. Typical use is a white underprint for an athletic look.

3. 110 mesh count - considered a medium course screen, it is by far the industries choice as the "do-it-all" mesh. Great for spot colors and text.

4. 156 mesh count - considered a medium screen mesh. It is commonly used for printing onto light colored fabrics with regular detail and medium ink deposit.

5. 200-240 mesh counts - considered a fine mesh count for printing onto white or light colored goods with a soft hand feel. Very good for high detail artwork. It can hold large halftone's but is not recommended for four color process prints or fine detail half tone printing.

6. 305 and higher mesh counts - considered very fine mesh counts is used for extremely high detail textile printing and fine halftone four color process and simulated process prints.