Screen printing is a century-old method of printing that uses a stencil to block ink from areas outside the design. In order to create the stencil, emulsion gets infused into a mesh screen and then exposed to UV light. This process “closes” the wires and strands, leaving only the area that is meant to print through. The screen is then used as a stencil to apply the desired ink to a substrate.
One of the first decisions that is made during production of a job is what substrate will be used. This will influence a wide variety of other raw material decisions such as inks, mesh counts and even screen fabric. There are many different types of mesh fabrics that can be used in screen printing, each with its own set of characteristics. A common choice for screen printing is woven stainless steel mesh, also known as sandpaper mesh.
The mesh size that is chosen depends on a number of factors, but the most important is what type of ink is going to be printed on the substrate. Higher viscosity inks may require a lower mesh count to achieve the same results as thinner, lower viscosity inks.
Another factor to consider is the level of contamination that needs to be removed. For example, hard particles like sand may be better removed with a coarser mesh size, while softer particles like lint or dust can usually be removed using a finer mesh.