Top 10 tips and tricks

Successful

Cap-

Printing Primer

BY ROGER L. JENNINGS

About the author: Roger Jennings is president of the R Jennings Manufacturing Co., an equipment manufacturer and printing-supplies distributor in Glens Falls, N.Y. Those seeking additional information should feel free to contact him at roger@rjennings.com.

creen-printed caps are one of the highest-volume apparel items sold. They also are one of the most profitable. Ironically, while most screen printers print lots of shirts, few compete for cap business because they don’t understand what it takes to be profitable in the headwear game. Successful garment printing starts with an understanding of what is unique about the item to be printed. Cap printing is actually easy for those who have mastered its special requirements. The tips that follow outline the shortest route to cap-printing success.

Match the cap to the customer

Young people—generally under age 30—are looking for low-profile, five-and six-panel caps that fit close to their heads. Their parents— from age 30 and up—generally wear a medium-height, five-panel, although the trend in this age group is also toward lower profiles. Think of the crown height as paralleling the age of the person wearing the cap. High-front-panel caps (more than three inches from the bill) and foam-fronts are still popular with the “retired: gone fishing” crowd and as an inexpensive giveaway item. If you want a successful cap program, give the customer what she or he wants. Kids won’t wear a foam-front cap, but they will wear a low— profile, six—panel . . . in the shower and to bed. Offering the right cap is the first step to success.

Youngsters spend the most for caps—easily $12-$l4 per cap and more. Check out the prices they’re paying at the local shopping mall to see what their price expectations are. For children, money is easy, because it comes from their parents. ‘The grandparents, by contrast, are the least fashion—conscious and most cost—conscious—and, therefore, are willing only to pay the lowest prices.

Pick the best cap for printing

Caps are decorated with embroidery, a variety of heat transfers and screen printing. The requirements of each are quite different. A screen printer who buys caps more appropriate for another decorating discipline is immediately in trouble. Starting with the wrong type of cap is the most common reason printers get discouraged with caps and eliminate this source of revenue from their businesses.

Stiff—front caps are better for embroidery. If you are a screen printer, don’t even think about printing caps described as “fused buckram” or constructed. Screen printers should only buy unconstructed,” “unstructured” or “half—moon-stay” caps. Foam-front caps are also a snap to print, if you can find a customer to wear them. Half-moon stays can be folded out of the cap with the sweat band to avoid interference with printing.

As for six-panel caps—with a seam running directly through the print area—those with tight seams and a smooth surface are the easiest to print. All others are more easily printed with three—dimensional or high—density (HD) Ink. HD ink looks and prints like other plastisols, but holds a sharp edge when a screen with a thick capillary-film stencil is lifted off the print. These inks work better with capillary— film rather than liquid—emulsion stencils.

Use high-tension screens

T—shirt printers have come to prefer tight screens when printing shirts, to hold registration, to prevent ink from building up under screens, and to realize other benefits. The same objectives exist for caps, but there is a problem. Cap frames must have one side very thin so the image can be printed close to the bill of the cap. Thin means weak. A weak side to the frame will not support the tension required for the highest-quality

printing. Therefore, I do not recommend wood or other types of rigid, none—retensionable frames. Only retensionable frames that take up tension from the side opposite the thin bar will draw the mesh tight enough to insure against ink smearing, heavy deposits of ink at the bottom of the image and other difficulties.

Use capillary-film stencils

Trough-coaters, even if the screen maker uses one under seven inches in width, do not develop coverage with emulsion to the edge of the frame. The coating at the edge will be thinner than in the middle, and is more likely to break down during printing, especially on a low—tension screen.

Capillary film is liquid emulsion coated onto polyester sheets in prescribed thicknesses. The thickness is selected according to mesh count and other criteria. A 110 mesh is typically coated with a 50-micron film (but could be coated with 40 to 150 microns).

As for materials cost (a reason many cite for not using film), consider

that a piece of capillary film suitable for a cap frame say four by six inches—would cost approximately one to seven cents per square inch, depending on thickness. Even though thicker films cost more, 50 microns (2 cents per square inch) of film would still be under 40 cents per screen (and considerably less per cap printed).

Capillary film is applied with lots of plain water and should overlap the thin edge of the cap frame. After the screen is exposed, the film overlapping the thin edge will either wrap around the thin side of the frame or drop off like an umbilical cord. This will cause the stencil coating to be of uniform thickness clear to the edge of the frame, in order to deposit a uniform amount of ink and prevent stencil breakdown.

Pinholes are typically eliminated with capillary film, and image quality is improved. When used in combination with three—dimensional inks and tight screens, cap features such as seams, sewn stitches, twills and even corduroy will be buried with ink that appears to be die-cut. Liquid—emulsion stencils do not perform this way.

Invest in a good squeegee

When pulling a T-shirt squeegee, notice how the corners deflect more than the rest of the squeegee. There is less pressure at the corners and, therefore, ink is sheared less successfully. As images can be exposed as close as 1/16” to the inside of a retensionable cap screen, the corner of the squeegee must not deflect more than the rest of the squeegee blade, if ink is to be deposited uniformly. A dual-durometer/triple-ply blade such as a 75-90-75 should be used so that the harder, 90-durorneter center ply prevents deflection at the corners.

The squeegee handle should be aluminum with the clamping bolts going through the handle rather than the blade. An aluminum clamping type handle provides uniform support to the blade whereas bolts through wood handles produce warped squeegee blades over time. Any squeegee should be sharpened at the beginning of each day. Just as a sharp razor cuts

better for a barber, a sharp squeegee cuts better for a screen printer.

Make sure ink shears easily

Have you noticed some colors are stiffer than others? The cornerstone of any quality program is consistency. In other words, inks should stir and shear the same, regardless of color. Accordingly, some inks will have to be modified. Inks should be stirred well, and the stir stick pulled straight out of the container. At six inches above the container, is the ink on the stick still connected to the ink in the container? If it is, the shear is poor and needs modification. After all, when printing off-contact we want the mesh to peel off the print surface and the ink to drop out of the stencil, rather than staying connected like the ink connects the stick to the can.

Inks can be modified by adding a measured amount of curable reducer typically only two to four percent by weight or by blending with ink that shears more easily. If the substrate is light in color, the blending can be with soft hand clear, which is ink without pigment. A three—dimensional ink, for example, might be mixed with an equal amount of a more printable ink that is not three dimensional, but still retains its dimensional characteristics in the finished image.

Adjust off-contact

When printing a white T-shirt through a thin stencil, an off-contact of 1/32” might be appropriate. Caps are often printed with thicker stencils to lay down a heavier ink film for an opaque image that can be seen easily from 15 feet or more. Three-dimensional inks may be printed 200 microns, 400 microns or even thicker, so need more off-contact distance to release ink from the screen.

Brushed cotton, for example, has fibers that will pick up when the mesh peels off the cap. Therefore, the off-contact distance when printing brushed cotton needs to be greater than when printing a tight-weave fabric, to help the ink in the image separate from the screen.

The easiest way to establish off-contact so the screen is perfectly parallel to the platen is to lay a piece of Plexiglas or corrugated cardboard——— at a thickness equal to the material to be printed plus the desired off—contact distance—on the platen. The color arm of the press needs to rest on the off—contact adjustment bolt while the screen is resting flat on the Plexiglas or cardboard. Positives can be placed on top of the Plexiglas or cardboard to register screens. When the Plexiglas is removed, the screen will be off—contact and parallel to the cap so a consistent amount of ink will he released.

Maintain consistent squeegee angle, pressure, speed

Many people printing caps have a tendency to rotate the squeegee when printing—typically by picking up their elbow during the print stroke. A great way to develop a consistent print stroke is to lock the wrist with a prescribed squeegee angle—such as of 45 degrees—then step back, using the entire body for the stroke, rather than simply pulling the arm back. After repeating this process for a while, the printer will be more sensitive to maintaining a constant angle, pressure and speed.

The pressure should only he sufficient to close the off—contact distance. Squeegee blades should never bend. Ink should be sheared and laid on top of the cap surface for maximum opacity and ease of curing. Ink driven into fabric will be less opaque and lose the resolution and sharp edge possible with less pressure.

Print six-panel caps

Six-panel caps command the highest profit margins and are easy to print when set up correctly. If the press is set up correctly, anyone can print a six-panel cap (or any other item). If the set-up is not right, even the most experienced printer will have trouble with six-panels.

To print six-panel caps with the seam in the middle of the image area, start with a piece of neoprene or similar material about 1/16” thick. Cut the neoprene in half, separate the two pieces by the width of the seam, and apply them to the cap platen. Lay the seam in the slot created between the two pieces of neoprene. If the seam is lower than the rest of the front of the cap—as cap seams occur in varying

thicknesses—build up the slot with layers of masking tape so that the front panel has no bumps or depressions when running your hand over the cap front. Now printing that six— panel should be no more difficult than printing a five—panel.

Beware the hold-down device

People frequently ask whether a hold-down device is required for cap printing. Generally, only a light mist of spray adhesive is necessary to hold a cap in place. If the mist adhesive will not hold the cap in place, then the style is either more suitable for embroidery or the cap is too small for the platen.

Caps are made from materials of different weights, some which stretch easily (such as foam fronts) and others which do not. Some hold-downs do not adjust well to different cap constructions and, as a result, may stretch the cap out of shape before printing, resulting in a distorted image after removing the cap from the press. Thus, if you’re forced to use a hold down for whatever reason, make certain you’re not buying more trouble than convenience.

Easy as shirt printing

Any time we learn to print something new, we must first figure out what is different about it, then learn to react to these differences. If you follow the 10 guidelines above, cap printing will be as easy as shirt printing—not to mention considerably more profitable, per hour.