Factors that determine which mesh you use

When choosing a screen print mesh size,  the first factor you should keep in mind is the level of detail of the image.  For example, your image has extremely high detail, and a low-grid screen cannot  retain detail at all. The thin lines or dots in the image will pass directly  through the holes in the grid, making it impossible for you to express what  your image should be. If your image is less detailed and uses too many grids,  you will run into insufficient ink to cover the shirt.
 Another important factor to remember is the  thickness of the ink itself. Thinner inks, such as water-based inks, usually  require higher mesh counts. If you use too few grids, thin ink may overflow  from the larger holes, causing your clothes to soak in more ink than expected.  When the ink oozes, flooding your clothes will blur your image. On the other  hand, if you are trying to print with thicker inks (such as plastisol or white  ink), you need to consider a lower number of grids. If the number of grids is  too high, you may encounter the problem that ink does not pass through the grid  easily, which may cause opacity and coverage issues.