If the quality of printing you are getting does not meet your expectations, the reasons are easy to spot. Selling a job that you are not proud to deliver does not have to happen again.

Whether you are purchasing for resale printed shirts, caps, tote bags, signs and the like, or you are the printer, you need to make sure the right tools are used to print your job. The tools include the screen, ink, substrate, emulsion, printing press, and that is just for starters. There are many choices available for each tool. These choices are not equal, and in combination with choices of other tools can produce brilliant results or disasters.

We will identify which tools are best, and why, and then suggest how these tools can produce new products for your customers. When you show fresh new looks in graphics your customers will respond with "wow," and you will have higher profit margin products.

Screen A screen can be wood, welded aluminum, or retensionable aluminum. Retensionable means either three or four sides of the frame are tubes that can be rotated to tighten the mesh through which the ink will pass. Any person who has printed even for a short time will say that tight screens are better than screens where the mesh moves in the direction of the print stroke.

Mesh can be stretched very tight on any of these frames, but will relax to almost no measurable tension over night. The welded frame holds the tension longer than wood frames, but only the retensionable frames permit taking up the slack in the mesh. Each time a mesh is retightened is can be tensioned to a higher level. The best screens have old mesh that has been retensioned at least 5-6 times and have been used for at least 500 prints. This process works the elasticity out of the mesh so that the print results will be more predictable.

The principal cause of heavy "bullet proof" prints is low tension screens. Ink may show on the inside of the garment for the same reason. Images where colors are not tightly aligned, or registered, to each other can be the product of soft screens. A dull image might be produced by ink pushed down into a fabric so that the customer is seeing both the fabric and ink color. Conclusion: make sure retensionable screens are used that have been used on several jobs before your job, and retensioned just before being used on your job.

Ink Any screen printer will admit that some colors and types of inks are stiffer than others. Some are like clay in the manufacturer’s container. Others can be loose and soupy, or someplace between clay and soupy. Quality depends on consistency and predictability.

Ink should be like yogurt when printed. If you stir yogurt up and remove the spoon from the cup, the yogurt drops immediately from the spoon. Ink can be whipped and blended with additives like curable reducer, soft hand clear or another ink to achieve the yogurt condition. Very few inks are shipped in this condition, and almost all inks need at least some modification.

Ink that is adhesive, remaining connected to the spoon when the spoon is 6" above the container, acts like an adhesive between the screen and article being printed. Adhesive inks may drag the mesh in the direction of the print stroke causing ink to smear and colors to bleed into each other. When the screen is raised, no ink should be on the bottom of the screen. When ink goes through a screen, but remains on the bottom of the screen, the image will have insufficient ink and likely be dull or incomplete.

The next time you have a job printed, ask the printer if the ink is whipped and modified to print like yogurt. Ask if the ink is tested to see if ink on the spoon is connected to the ink in the container when the spoon is 6" above the container. You will be surprised by the answers you get to these basic tests.

Substrate A substrate can be a hard, smooth surface like a sign, label or bumper sticker, or a porous shirt, or textured surface of a tote bag. The substrate can be white, black or some other color. A heavy deposit of ink on a hard, smooth surface is more likely to smear, but the same quantity of ink may be insufficient to produce an opaque image on a dark, porous or textured material.

Upon inquiry, the printer should tell us the mesh count, stencil thickness, type of ink and other procedures to be used to compensate for the substrate condition. A response that does not, at a minimum, address these evaluative criteria – mesh count, emulsion thickness and type of ink – is a precursor to unsatisfactory quality.

Emulsion Emulsion is a material in the mesh that blocks ink from passing through the mesh, except where the image will be printed. Emulsion can be applied as a liquid to mesh or purchased as a dry sheet known as capillary film that is applied to the mesh with water. A liquid emulsion encapsulates mesh, but capillary film sticks to the bottom of the mesh.

Capillary film produces better quality images, but is not widely accepted and used like liquid emulsion. Capillary film can be purchased in different thicknesses, and can be laminated to create thicker coatings under a screen as a way of controlling the amount of ink that is deposited to compensate for the substrate conditions. Screen printers who do not use capillary film extensively do not know what they are missing. You and your customer will be missing the opportunity to produce the best quality images and new, high profit margin products.

Press A printing press provides the foundation to an image. If the print surface of the press moves when you press down, you will have a shaky foundation to the print quality. The color arm of the press should not move laterally when down in the print position or allow any twisting when you try. If there are a multiple of print surfaces upon which garments are placed, they should all pass under the flash dryer at exactly the same height. This can be checked when the flash dryer is turned off and paper taped to the dryer to check the consistency of printing height and level of all printing surfaces.

If your work is being printed on an automatic press, do you hear "clang and bang," feel or see movement in the print head during the printing process? A well maintained press will only whisper, print without shaking, and not have to be lagged into the concrete floor.

Curing A common complaint with printed apparel is the ink fades or washes out, or can even be picked off the shirt. When you receive an order you can check whether this will happen or not. Stretch the image. If it cracks, the ink is not fully cured. Try to pick the ink off with your fingernail. If the ink comes off, the ink is not fully cured. Ink that is not fully cured will wash out or fade from washing.

When ink does not pass your stretch or pick tests, return the garments to have the curing job finished. Curing inks is like baking cookies. Soft centers are under cooked or cured. All inks should be like well done steaks and not rare or medium cooked steaks. All the printer has to do is run the garments through the dryer again, but this time slower and on lower heat so the heat penetrates the ink film without scorching the garment.

Positives If shaded colors or so-called "process" work is the requirement, the "positives" should be inspected. Positives are the image on vellum paper or plastic that allows light to pass through, except where the image will appear. Shaded or process images should appear as individual, dense black dots separated by clear areas where no gray or black appears. If the image is continuous tone gray rather than individual black dots, the image quality will be poor.

Other Questions Other questions you can ask to protect your reputation for delivering quality include: (1) How far off-contact will you be printing? The mesh should be off-contact from a sign or other hard, smooth material 1/32-1/16". The off-contact for a T-shirt should be 1/16-1/8". A sweatshirt will be 1/8-1/4". (2) Do you sharpen the squeegees daily? The answer should be yes, but most will say no. A sharp knife works better in the kitchen, and we are cutting ink to be laid down in thin, controlled deposits.

(3) Do your squeegee blades bend? The answer will probably be "of course," but the answer should be no. Bending blades are a sign of excessive squeegee pressure that will splatter ink on a hard surface or drive ink into a fabric. We want crisp images lying on top of the surface.

These criteria to control the quality you will be receiving are also the starting point to new product offerings at superior profit margins. The market in apparel, for example, has broadened from T-shirts to textures like pique golf shirts, denim collared shirts, 600 denier tote bags and twill aprons. Most of this market is served by high priced embroidery. The high price can be charged, but the image printed with photographic quality, with fonts, details smaller than ¼" and even dots reproduced exactly as they would be in advertising, packaging and on stationary.

This new process requires the retensionable screen, capillary film, 3-D ink, and a press that does not flex during the printing process. Actually, layers of ink can be laid one upon the other so bumps appear on a basketball to create a realistic effect. Images can be printed with the 3^rd dimension that stands off the garment. Such textured images are sharper looking than embroidery, more flexible and comfortable to wear, quick to print and deliver like any screen printing, but high priced like embroidery.

So the next time you order screen printing, ask the right questions before selecting your printer rather than risking losing a customer after you deliver the order.

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Roger Jennings can be reached at roger@rjennings.com to ask questions. Additional support is available on www.rjennings.com. Roger is President of

R Jennings Manufacturing Company which makes screen printing equipment. He holds numerous patents and has contributed articles and conducted industry seminars for over 20 years.

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