Different mesh sizes are used for different applications in the screen printing process. What is mesh size? you might ask. Well, mesh size is a measure of how many threads of polyester (used to be silk, centuries ago, hence ‘silkscreening!’) cross each other per square inch of screen. For example, a 110 mesh screen would have 110 threads crossing per square inch. The higher the mesh count, the finer the holes are in the screen.
The first factor you should keep in mind when choosing a mesh size is how detailed your image is. If, for example, your image has extremely high detail, a low mesh screen simply wouldn’t hold the detail. The fine lines or dots in the image would simply fall through the holes in the mesh, leaving you with a poor representation of what your image should be. If you have a low detail image, and you use too high of a mesh count, you'll run into issues with getting enough ink to lay down on the shirt.
The other important factor to keep in mind would be the thickness of your ink itself. Thinner inks, such as water based, generally require a higher mesh count. If too low of a mesh count is used, then the thin ink could potentially flood through the larger holes, soaking your garment with more ink than intended. This would make your image blurry as the ink bleeds. On the other hand, if you’re trying to print with a thicker ink, such as plastisols or white inks, you’ll want to consider lower mesh counts. Too high of a mesh count and you may run into an issue with inks not easily wanting to pass through the mesh, which could lead to opacity and coverage issues.
You will notice that different companies have different sizes available. If the mesh count is fairly close, such as the difference between 155 vs. 156, 196 vs. 200, or 81 vs. 86, the difference is so negligible that it will not matter in your final results. Since there are many variables involved in silk screen printing we can’t tell you exactly what mesh sizes are used for what applications. However, we can give you a general outline of what sizes to use for certain types of printing.
The two most standard mesh sizes are 110 and 156. 110 mesh will lay down a fairly thick layer of ink. It is great for block text letters and larger spot color designs. It’s also a recommended mesh for white flash plates (underbase) because many times you will only have to do one print, which speeds up production. 156 mesh will lay down a moderate amount of ink, but offers more detail capability for your image.
There are mesh counts lower than 110, and they are most often used for specialty printing. The major place you will see lower mesh counts used is for glitter and shimmer inks. These inks are made special to have flakes of glitter in them to give the desired look. These flakes can get caught in the mesh of your screen if your mesh count is too high. This would result in all the particles being stuck in your screen, and none going onto the shirt itself. Glitter inks have larger, more obvious flakes to them, while shimmer inks will have smaller particles to give a more subtle look. A mesh size of 36 is ideal for glitter inks, though you can go up to a 64 mesh. For shimmers, an 86 mesh is recommended.
Higher mesh screens, 200 mesh and above, are most often used for finer detail images and thinner inks. Graphic, solvent based, and water based inks should be printed through screens of this mesh size. The higher mesh count helps to keep the thinner inks from flooding onto your substrate. If you would like to get a softer hand feel to your plastisol prints, these higher mesh counts can help as well. By printing the thicker ink through the finer mesh, much less of it is laid down, allowing a thinner ‘plate’ of ink. This results in a softer feel to the print. This can get tricky, however, as it might sacrifice the opacity of the ink. If your design is meant to have very bright, vibrant colors, pay attention to how much ink your screen is letting you print.
At the top end of the scale, you have a 305 mesh. This size is used for jobs with the highest level of detail, and fine halftone four color and simulated process prints. Fine half tone dots need very high mesh counts in order to hold and expose properly. Otherwise, as stated before, the halftones and lines will simply fall through the mesh, leaving you with a less than desirable image to work with.
Mesh counts above 305, such as 355, 380, and 400 are mainly used for graphic printing with UV inks. UV inks are extremely thin, and many times are used for high detail printing on signs, banners, or CDs. Using a higher mesh allows the automatic printers used in UV printing to regulate the amount of ink passed through the screen.
One last thing to consider is that different mesh sizes hold different amounts of emulsion, due to the differences in the mesh’s holes, and that can affect your exposure times. For instance, a 110 mesh screen will hold much more emulsion than a 305 mesh screen. While the difference isn’t extreme, you will have to vary your exposure times slightly for different mesh sizes. A finer mesh screen will expose faster than a lower mesh screen because of this. The difference is small enough that you should only have to vary as much as 5-10% in either direction, dependent on the mesh size.
Mesh count is a major factor when considering your print job. Too high or too low can disrupt your job and leave you with a less than desirable print and a lot of frustration. Always keep in mind what ink you're using, and what kind of design you're printing, and you'll be choosing the right mesh counts without a second thought in no time.