“Tattooed Lady” was printed at 85 LPI, using a combination of 180/48 micron and 330/30 micron mesh. The close-up view shows the ultra fine detail achieved through the use of thin thread mesh and proper stencil making. (All images and diagrams courtesy Motion Company)

In a recent article published in Printwear (see March 2010, page 52), I listed some of the key innovations in modern screen making. The item at the top of the list is one that I deemed to be so important I promised to cover it in a future article. So alas, welcome to the wild and exciting world of... thin thread mesh? Okay, maybe not wild and exciting, but for textile printers looking to improve the quality of their product, this topic won’t disappoint. 

 

What is thin thread mesh and why should I care?

Thin thread mesh is a fabric comprised of monofilament polyester thread which is both thinner and stronger than that used in traditional screen mesh. It provides better memory, reduced fabric interference and a greater percentage of open area at moderate tension levels. These unique features result in improved image detail, opacity and hand. Originally developed for filtration—believe it or not, the primary industrial use of mesh is in filtration—thin thread mesh was first adopted by textile screen printers in Japan, mainly for water-based printing on high-end fabrics such as silk. Early on, thin thread mesh was simply mesh comprised of thinner, but not stronger, thread and lacked the stability and durability to meet the demands of textile printers throughout the rest of the world who were using heavy plastisol inks on coarse substrates. 

Over the years, manufacturers of thin thread mesh improved their products to meet the demands of textile printing by increasing the tensile strength of the polyester thread itself. Coincidentally, ink technology has also improved, printing higher-quality substrates has become commonplace and thus, thin thread has become a viable technology for all textile screen printers.

c. When a readily-available product or technology will improve print quality at little to zero additional expense and make printing easier and more efficient, which will probably save money anyway, you would be foolish not to care.

 

“Three Ring Circus” was created using discharge ink printed through 150/48 micron mesh. Note the clean, crisp lines achieved through the use of thin thread mesh. Prior to implementing thin-thread mesh technology, the author reports he would have utilized traditional mesh in a lower thread count, which would not have held the same level of detail.

Technical features and benefits of thin thread mesh

The most important feature of thin thread mesh is the smaller thread diameter itself, hence the term ‘thin thread.’ To make a comparison between the thread diameter of traditional mesh versus that of thin thread, let’s use a common mesh count, 110, and compare it to a 150 thin thread mesh. The thread diameter of a typical 110 mesh will measure 80 microns, while the thin thread 150 mesh will measure only 48 microns in diameter. So, what’s the big deal with 32 microns of thread diameter? Increased open area (OPA%).

The reduction of thread diameter results in an increase in OPA% over traditional mesh. Increased OPA% allows for greater ink saturation of the print area, improving opacity and vibrancy of the printed image. In the past, the only viable method of increasing OPA% was through the use of high-tension mesh comprised of high density, large diameter thread (100-plus microns) stretched to extremely high tension levels (60-plus N/cm). 

Although high tension printing has been successfully employed by very advanced print shops for many years, it is hardly practical for the majority of screen printers. It should also be noted that increased OPA% allows for ease of ink flow with minimal squeegee pressure which, in-and-of itself, dramatically improves print quality and consistency.

Working off of the 110/150 mesh example above, the OPA% comparison looks like this:

If the conventional wisdom among textile printers holds true—lower mesh = more ink = better opacity—then the comparison above has successfully defied such conventional wisdom. The thin thread in a higher thread count has an increased OPA% over that of the traditional mesh in a lower thread count. So what’s the big deal with an 8 percent differential in open area?

 

Fabric thickness and ink volume

There are real advantages in printing through thin thread mesh of a higher thread count; the first of which is in fabric thickness. Thin thread mesh exhibits a reduced fabric thickness over traditional mesh. Printing through a thinner fabric results in a thinner, more even ink deposit and yields a softer hand. The finished print will exhibit a smoother finish both in a tactile and visual sense. 

Working off of our 110/150 mesh example, a fabric thickness comparison looks like this:

Another advantage: Ink volume. Let’s reevaluate the conception of “more ink = better opacity” in the aforementioned conventional wisdom held by textile screen printers. This point is only partially true to the extent that, yes, a minimum amount of ink must be deposited onto the substrate to properly penetrate or matte down the garment fibers. However, the reality is that image opacity is affected by factors beyond ink volume, i.e. substrate and ink characteristics, not to mention design characteristics. And with a sound understanding of these factors, any printer should be able to achieve sufficient opacity without resorting to the application of an excessive amount of ink. 

In fact, under typical printing conditions, a smooth and even deposit of a minimal amount of ink will deliver a more vibrant and opaque print than simply applying an excessive volume of ink. This is to say nothing of the desirable hand characteristics achieved through proper application of minimal ink volume and the undesirable hand characteristics achieved through excessive ink application. 

A comparison of the theoretical ink volume of our 110 and 150 mesh shows a 19 percent differential in theoretical ink volume:

Real-world application

So now that you have learned about some of the features and benefits of thin thread mesh: What does thin thread mesh really do... in the real world?

Since implementing thin thread mesh technology in my shop, we have seen a dramatic improvement in print quality and efficiency from basic spot color to special-effects printing. The hand of our finished prints has become softer and smoother as we are able to deposit a thin and even layer of ink onto the substrate without sacrificing opacity. The ease of ink flow as a result of increased OPA% has allowed for reduced squeegee pressure, improving both registration and image detail.

This illustration represents a close up comparison of 110/80 micron mesh and 150/48 micron thin thread mesh. Look closely within the star shapes and around the border to note the difference in space between the mesh cross-sections. The 150/48 mesh on the right has a higher OPA% than that on the left, resulting in greater ink saturation.

Specialty printing such as discharge—which requires a large OPA% and is typically produced using screen mesh counts in the 86 to 110 range—has become easier as the increased OPA% of thin thread mesh helps to keep ink from drying in the screen. Plus, through the use of higher mesh counts (135 to 180 range), we are able to hold a level of detail that is not possible with lower mesh counts.

Our halftone printing has benefitted from the elimination of fabric interference. A common cause of moire patterns in halftone areas is fabric interference. This is when the threads in the mesh literally block halftone dots, thus not allowing ink to fill the stencil cavity. With thin thread mesh, the thread is small enough as to not block the halftone dot, allowing ink to flow into the stencil cavity. Since switching to thin thread, we are able to print halftones in the 65 LPI to 85 LPI range without having to battle moire caused by fabric interference.

While it is true that no single product or technology by itself can guarantee quality printing, certain products and technologies can dramatically affect the screen-printing process and lead to quality printing results. Thin thread mesh is a technology that will improve the screen-printing process for experienced and novice printers alike. 

For the beginner, thin thread mesh provides a key solution in building what is the foundation of the screen-printing process: the screen department. For the advanced printer in search of perfecting the craft, thin thread mesh will enhance both the quality and efficiency of the final product. Take the time to do some more research. Thin thread mesh is offered by a number of manufacturers, any of which will be happy to overwhelm you with technical information. Or contact a local screen-printing supply house and inquire about available screen mesh selection… just don’t be surprised if, when asking about thread diameter, OPA% and fabric thickness, you receive a huh? in response.

 

This illustration represents a close up view of the mesh opening and the formula from which OPA% is derived.

Fundamentals of Mesh

 

Here are some of the common terms­—and their definitions—used in discussions about screen mesh.

 

Material—Polyester is the material most widely used for textile screen printing. Other materials commonly used to manufacture mesh include rayon, nylon and stainless steel wire. Silk has not been used commonly in screen printing for decades—why we no longer refer to the craft as “silk screening.” 

 

Fabric color—Standard non-dyed polyester mesh is white in color. Dyed mesh, typically yellow or orange, is used to minimize halation: the spreading of light beyond its proper boundaries.

Tension—The tension level of stretched screen mesh, measured by Newtons Per Centimeter or N/cm.

 

Mesh count—The number of threads per linear inch or per linear centimeter of screen mesh.

 

Monofilament thread—Thread comprised of a single filament.

 

Multifilament thread—Thread comprised of multiple filaments twisted together.

 

Weaving pattern—The pattern in which the thread is woven. The most common weave for textile printing application is plain weave: a pattern of weave whereby the warp and filling thread (weft) cross alternatively over one and under one. Plain-weave mesh is the least pliable but most stable.

 

Thread diameter—The diameter of a single strand of thread, measured in microns.

 

Open area (OPA%)—The percentage of open area of the mesh at a specific tension.

 

Fabric thickness—Also known as mesh thickness, the total average height of two crossing threads in a woven screen mesh measured under tension.

 

Theoretical ink volume—The mathematical representation of the volume of ink in a mesh opening, typically measured by cubic centimeter (cm3), that is calculated from the open area and mesh thickness specifications.