Screen Printing Mesh: Count Conversions, Thread Diameter and Everything

Nov. 15, 2012 - PRLog -- It is often the case that mesh count nomenclature causes confusion with people first learning to screen print. There are a few different ways of referring to mesh that are from the past or from Europe that we may see floating around the internet. As you search for information to better help you understand screen printing, these differences can be a problem. The following is an attempt to bring all of this information together for you to easily digest and refer to.
Most mesh today is monofilament, (see the end of this article for more about that). In the United States you will often see specifications for screen printing mesh that looks something like this:
355-34Y PW or 355/34
The number 355 represents the mesh count of 355 threads per inch. The number after the dash, in this case 34, refers to the thread diameter. The thread diameter, mesh count, and solid content of the ink will determine the amount of ink that passes through the mesh.
The letter Y tells us if the mesh is yellow or W for white. Those are the two most common colors of mesh.
The letters PW refers to the weave type of the mesh. PW stands for plain weave andTW stands for twill weave.
All of these numbers and letters ultimately refer to the mesh geometry and performance which is important to understand. Mesh geometry is the description of all two and three dimensional aspects of the mesh construction. The two basic factors in mesh geometry are the mesh count and the thread diameter. The mesh count refers to the number of threads per inch contained in the mesh. The thread diameter refers to the diameter of the thread before it has been woven into the mesh.
The thread diameter and mesh count together determine the mesh opening. To put it very simply, mesh opening is the spacing between adjacent threads. Mesh openings dictate the maximum particle size you can use in an ink and it affects the overall detail printed as well as the ink release characteristics. For best ink passage through any mesh count, the maximum particle size must be smaller than 1/3 of the mesh opening.
It is important to remember that mesh geometry will define the characteristics of the mesh. The mesh opening, mesh thickness and the theoretical ink volume obtainable by the mesh are all determined by mesh geometry.
Mesh geometry affects:
•   Printability of fine detail, lines and halftones
•   Crisp resolution of edges in the design
•   Ink release properties
•   Printing speed in relation to your ink viscosity
•   Ink volume thickness
•   Ink flow & consumption during printing
In the United Kingdom mesh is measured in threads per centimeter. There is a rule of taking the US number (inches) and divide by 2.5 to get the UK thread count conversion.
For example:
110 divided by 2.5 equals 44. This is closest to a 43T English or “European” measurement. The T is the Swiss method of telling you the thread diameter of your mesh. Usually, mills make mesh in 3 thicknesses with 3 thread diameters.
S = small thread diameter
T = medium thread diameter
HD = heavy thread diameter
S is the thinnest diameter and permits higher squeegee stroke speeds but normally requires high quality stencils. T is a medium diameter for soft hand printing as well as printing wet on wet on darks. HD is the thickest diameter of the three and requires a slower speed with a thicker stencil and a soft squeegee.