Selecting the Right Mesh

Narrow your options to improve your results

"What mesh should we use for this job?" That's a daily question in many screen-printing shops.

Which mesh will best meet the conflicting requirements of ink, design, and garment? Your answer to this question will have a dramatic effect on the printability, appearance, and feel of the designs you print.

Mesh selection is a series of compromises. If you select a coarse mesh, the ink will pass through the screen easily but the ink will be thick and you will be unable to print fine details. If you select a fine mesh, you will have difficulty printing a bright design on dark-colored garments. Furthermore, some types of inks will not print through fine meshes. And these are only a few samples of the many mesh-selection problems available for the textile screen printer to choose from or blunder into. In this chapter, I'm going to provide general guidelines for mesh selection and then list suggestions for common ink/design/garment combinations.

General Mesh Specifications

To start, all the screens you use should be meshed with monofilament polyester fabric. Although other meshes are available for printing garments, monofilament polyester is the best option for strength, durability, controlled elasticity, and reclaimability.

You should use plain-weave mesh rather than twill weave. Twill weave mesh is only found in the higher mesh counts (above 300 threads/in.).

High mesh count fabrics are primarily used to print fine details and halftones. Unfortunately, twill-weave mesh interferes with fine details and causes severe moiré problems.

Polyester mesh is usually available in both standard and low-elongation versions. The term "low elongation" is used to describe mesh that, either because of the chemical structure of the polyester or the way it is processed during and after weaving, or both, will show less loss of tension than standard mesh after it has been properly stretched. Low-elongation mesh is a good investment if you use a tension meter and retensionable frames. Otherwise, save money by buying regular mesh.

Mesh is available in white and a variety of colors. Colored mesh is preferable in the higher mesh counts because the filaments in a white mesh act exactly like fibers in a fiber optic system: tiny "light pipes" that carry light into areas of the screen where you don't want it to go. This light scatter can make it difficult to accurately image a screen with fine details or halftones. Colored mesh, on the other hand, will not transmit wavelengths of light that affect light-sensitive emulsions. I recommend that you always order dyed mesh any time you are pruchasing mesh over 140 threads/in. Dyed mesh with a mesh count of less than 140 threads/in. is not necessary because mesh that coarse does not hold sufficiently fine detail to be affected by light scatter.

Mesh Count

There are well over 400 different meshes sold in the United States. To say that this is overkill is an understatement. A review of literature listing available meshes is likely to result in more confusion than information. There are two ways to solve this problem. You can either spend your Saturday mornings studying all the available information on every mesh and mesh selection procedure, or you can make an arbitrary decision and select a limited number of meshes for further consideration.

I have chosen the second procedure, listing 11 meshes (Table 1) that will handle all the textile screen-printing situations the average screen printer is likely to encounter. Every experienced screen printer glancing over this list will notice that some of his or her favorite meshes were omitted. But the point of this list is to provide a reasonable number of meshes that will work well in the maximum number of situations.


 

Table. 1 The Eleven Meshes
Nominal                                             Woven                          Thread Diameter
Mesh Count1                                Mesh Count 2                    Diameter
(threads/in)                                    (threads/cm)                         (microns)

380                                                        150                                       31
355                                                        140                                       34
305                                                        120                                       40
280                                                        110                                       40
230                                                          90                                       48
195                                                          77                                       55
140                                                          55                                       64
110                                                          43                                       80
86                                                            34                                      100
74                                                            29                                      120
38                                                            15                                       200


1. This is the actual mesh count for meshes woven in Japan.
2. This is the actual mesh count for meshes woven in Europe.

The Eleven Meshes

Consider the advantages of limiting your mesh selections to these 11 meshes. You limit the variables your production people have to deal with, from creating the design to printing it. You limit confusion in the screenroom. You will learn to adjust your ink to your mesh, rather than the other way around, thus establishing a much more economical and efficient process. Hypothetically, if enough screen printers adopted these meshes, the manufactureers would be encouraged to produce fewer types of mesh in larger quantities. Theoreticaly, this would mean lower mesh costs.

What are the advantages of selecting your meshes from the entire list of 400 meshes available? Well, you can spend countless hours studying mesh manufacturers' spec sheets. You can play trial and error with scores of different meshes in an attempt to find the absolutely perfect mesh for each different job. You can confuse your screen department beyond recovery. Is this a 110 or a 115 mesh? There are nine different meshes available in the 110-120 threads/in. range alone. How important is it to select the one perfect mesh for each job from among those nine meshes?

Is it possible to identify specific printing situations where a mesh that is not on our list will, theoretically at least, be a better choice than one of our 11 meshes? Certainly. But remember, the 11 meshes we have listed will perform adequately to print any design on any garment. Any adjustments to improve the printed image can be made in the ink, press setup, and printing stages, rather than by endless trial and error to find the one perfect mesh among 400.

General Advice

The historic rule for mesh selection was to use the coarsest mesh you could that would still hold the detail you needed. This rule originated in the days when you needed a lot of horsepower to push plastisol ink through the mesh. This rule has been challenged over the last few years by many experienced screen printers who want to print the thinnest possible ink layer in order to obtain ultra-soft-hand prints. The trend toward thin ink layers and soft-hand prints has required that screen printers learn to print through finer meshes. They have achieved success in this by using well-tensioned screens and plastisol inks that combine excellent printability and high opacity.

The phrase "fine detail" is bound to be used when screen printers give advice about mesh selection, but it is never explained. Certain meshes are often recommended for printing designs containing fine details, but there is no general agreement in the textile screen-printing industry as to what, exactly, a fine detail is. When you are discussing mesh selection, fine detail is not necessarily the point at which the image becomes difficult to print. Instead, it is the point at which the nature of the design has a decided effect on which mesh you choose to print the design with. I think that it is reasonable to say that a line that is fi-point wide (about seven-thousandths of an inch) would be considered fine detail in most textile screen-printing shops. Similarly, a 20% dot in a 30-line halftone can be considered fine detail.

The guidelines for mesh selection provided here will certainly get you in the ballpark. However, they are just that&emdash;guidelines. The best source of information to help you solve your mesh-selection problems is your own production records, assuming of course that you maintain complete and accurate production records. To help solve your mesh selection problems, record the following information about every job that you print:

mesh type (mesh count and color)
screen tension
type of ink
ink modifications
type of design (single color, multicolor, process color, fine details required, etc.)
garment type
garment color
garment-fiber blend
printing problems, if any.
Reviewing this information regularly will help you learn what mesh counts provide the easiest, best prints under all your production conditions.

Ink manufacturers are another excellent source of information to help you with your mesh-selection decisions. Most fo the ink manufacturers provide technical data sheets. Although the information on most of these sheets is usually very general (recommending mesh counts from 110-355 threads/in. does not help the average screen printer narrow down the choices much), it will provide you with outside parameters and suggestions for special situations.

 

Table 2 lists mesh selections that will work well in all common textile screen-printing situations. If you wish to experiment, start with the corsest mesh and then work your way up to the higher meshes listed. You may also find that the higher mesh counts are good choices if you are printing with an automatic press or with meshes that have ben tensioned to the mesh manufacturers' recommended tension level.

Table 2. Ink/ Mesh Combinations
Ink                                                                 Recommended Mesh Count (3)
Glitter Inks(4)                                              38, 74, 86
Puff Inks                                                      74, 86, 110
Puff Inks used as an underbase           140
Suede Inks                                                195, 230
Metallic Inks                                              74, 86, 110
Fluorescent Inks                                      74, 86, 110
Water-based Inks(5)                               110, 140, 195


3. Mesh counts are for thread/in.
4. Some glitter inks require coarser meshes.
5. Mesh count does not have as much effect on hand and opacity when printing water-based inks as it does with plastisol inks. You can achieve soft hand at much lower mesh counts and good opacity at much higher mesh counts with water-based inks than with plastisol inks.

Ink

Regardless of shirt type or design, some inks require special mesh considerations. Be careful in selecting the meshes you use with these inks. See Table 3.

Table 3. Design/ Garment/ Mesh Combinations
Design/ Garment Combinations Recommended Mesh Count
Light Colored T-shirts
Ordinary single-color print 110, 140, 195
Ordinary multi-color print 140, 195, 230
Detailed print 195, 230, 280, 305
Halftones and process color
305, 355, 380
Dark Colored T-Shirts
Heavy coverage 74, 86
Underprint 86, 110
Detailed print
86, 110
Nylon Jackets
Light-colored garment 195, 230
Dark-colored garment
110, 140
Special Situations
Athletic prints 74, 86
Overprint colors 195, 230, 280
Water-based ink on towels 74, 86


One Last Tip

Of course, the mesh-selection challenge you face most frequently is determining what mesh is on the frame you are holding in your hand. Here's a tip from Nancy Gray of Stretch Device: Write the mesh count on the frame if it's wood, or on the mesh in a corner of the frame if the frame is metal, with a permanent, black, fine-point, felt-tipped marker. To protect the number from being erased by screen-reclaiming chemicals, paint over it with polyurethane varnish if you wrote the number on a wood frame. And if you wrote the number on the mesh, apply frame adhesive to both sides of the mesh over the number to preserve it.
 

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