Advertisement

Resort-style prints

At 21 years old, Lon Winters was the production manager for Ocean Pacific and started his 30+ year career reclaiming screens. His companies have won 50+ garment decorating awards and honors, and he's served 15+ years as an honorary Golden Image Judge, published hundreds of articles and columns, led various industry seminars and workshops, and consulted on projects large and small. He's the president and founder of Colorado-based Graphic Elephants, an international consulting firm and apparel decoration studio specializing in screen printing technical advances, plant design, layout, troubleshooting, productivity, quality analysis and complete apparel decorating solutions. He was inducted into the Academy of Screen Printing Technology in 2013 and is recognized for his contribution to the graphic printing industry.
www.graphicelephants.com.

Whether for a mountain ski community or hotel retailer, the resort market offers creative opportunities for decorated-apparel success. Like most decorated-apparel niches, the resort market is plenty competitive—you’ve considered breaking into this market, you’ve certainly got some research to do.

In terms of what is hot, the world of decorated resort apparel always seems to be cutting edge. It is important to stay on top of trends such as water-based and discharge screen printing, oversized and over-seams printing, out of the ordinary placements, foil and rhinestone bling, and even multimedia combinations of embroidery, appliqués, transfers, inkjet and screen printing. But of all of these, water-based and discharge printing have been steadfast within even the sharpest cutting-edge markets.

Discharge printing embellishments are nothing new to the decorated-apparel industry. In fact, this method of water-based printing on dark fabrics has been around for decades. While many screen printers may have been familiar with this printing technique for years, it has resurfaced with enormous popularity at the retail level. Many major brands use discharge screen printing to achieve an ultra soft-handed print on garments, some of which hang an $80-plus price tag on their trendy Ts in retail stores.

Discharge defined

Discharge inks are a part of what we would call today‘s specialty screen printing. The word discharge refers to a chemical reaction that destroys the ability of certain dyes to reflect color. The technique uses a chemical to remove color from a 100 percent cotton reactive-dyed garment—the discharge agent in the ink effectively breaks down the dye of the fabric, leaving it un-dyed or natural in color. This natural color is called the original greige goods (pronounced and also referred to as “gray” goods—simply, a textile that has not received any bleaching, dying or finishing treatment). That color is replaced by the pigment color in the discharge ink.

Only reactive-dyed fabrics will discharge, and even then, not all 100 percent reactive-dyed cotton garments discharge. Over-dyed, garment-dyed or other pigment-dye processes do not discharge. Most darker-colored reactive-dyed fabrics seem to discharge quite well, while lighter colors sometimes do not. Blues, reds and purples are particularly troublesome.

The process generally eliminates the need for a white under-base print and multiple flashing, which is typical of more conventional techniques used when printing with plastisol. Though available in plastisol form, printers usually opt for the water-based version on dark garments, as it results in that extremely soft hand we are constantly chasing. No other process produces such a soft, breathable, absorbent, bright colored print on dark garments. And, it’s ironable to boot.

Discharge is usually a water-based screen-printing method. The majority of the ink has a water-based component as its base. Zinc formaldehyde sulfoxylate (ZFS) powder, the activator, is added to the discharge base in a six to 10 percent ratio. A third component of pigment can also be added to the mix. The discharge is then screen printed onto 100 percent cotton reactive-dyed fabric. Water-based discharge prints can achieve the opacity of plastisol in addition to a very soft hand on dark-colored garments.

Standard discharge “clear” can be used as a stand-alone ink or as an under-base for other colors—either water based or plastisol—to be over printed. Pigmented discharge screen printing is another method, where a garment is discharged as described above, but rather than turn the shirt to its natural color, the color is actually removed and replaced with the pigment color.

This printing technique can have various and sometimes unpredictable results. Variations in a garment dye’s ability to be discharged, ink viscosity due to evaporation of water from ink in the screen, print technique, dryer temperature and airflow make absolute control of color matching nearly impossible. Though several major manufacturers are working on what they call a “dischargeable” standard color palette, testing is still needed. If a printer is to maintain any semblance of color uniformity throughout a run, and from run to run, garments must discharge to the same base color. Sometimes this can be difficult, but is becoming easier as garment manufacturers seek to capture this hot market as well.

As with any ink system, keeping good records of how discharge ink colors are mixed, the screen particulars and other specifications is essential if colors will need to be duplicated for reorders. There are some systems that allow the mixing of Pantone colors using formulas with fair results.

Soft-handed perception

Discharge screen printing is one of the options being touted as a greener alternative to standard plastisol inks even though the activator in most discharge printing systems is Zinc Formaldehyde Sulfoxylate (ZFS). Perhaps this is due to the newer discharge systems available that are formaldehyde-free or non-formaldehyde (NF). The new NF products perform very well and have less health and safety concerns as those containing formaldehyde.

The non-formaldehyde formulas typically perform very well. Garments printed with such inks can be worn without washing, whereas those printed with ink systems that contain formaldehyde should be laundered prior to wearing to prevent any potential skin irritation.

It should also be noted that the non-formaldehyde inks can sometimes have a more limited pot life than the typical eight to 12 hours that the ZFS-containing discharge inks carry, though there are some products with an even longer life being tested and used today.

Formaldehyde or no, the same rules apply for any ink system: Proper safety and health recommendations should always be followed. Printers should always follow MSDS recommendations for cleanup, contact with skin, eyes, ingestion, and so on with any ink system.

Precautions should be applied to clean-up as well. Unlike traditional plastisol ink, water-based ink systems don’t require solvents for clean up. They will clean up easily with just that, water. But, please note that just because we hear the word water, it does not mean the ink may be washed down the drain into the sewer. Water-based inks contain pigments, binders, thickeners and other materials that should be disposed of properly.

Pre-press practices

Working with discharge inks may be challenging in the beginning, but can become much easier with a little knowledge and some experience. Since discharge printing is typically done with a water-based ink, the screen will require a water-resistant stencil. Longer runs may require adding a hardener to the water-resistant emulsion so the stencil doesn’t break down during the run. Some hardeners will make the stencil permanent—not really what we want if we are using retensionable frames—so you’ll want to use a reclaimable hardener.

The most common mesh choice is 156 tpi or lower. Plastisol printers who have long used meshes as fine as 380 monofilament polyester will find they are limited to meshes of 195 and lower when printing with water-based inks. This is because of the size of binder particles. Also remember: The finer the mesh, the faster the ink can dry in the screen and cause clogging.

A new generation of water-based inks are now available that can be used with much finer screen meshes. The newer inks allow as high as 305 for very fine detail, but note that the printing process becomes much more involved at this level.

Production climate control is important as well to keep water-based inks wet. Humidification may be necessary, especially when printing in a dry climate. This can be achieved by keeping misters, buckets of water or humidifiers on hand during printing. Good air flow is required to cure discharge inks, but the same air flow that enhances curing is an enemy when it comes to the printing process, causing water-based inks to dry in and clog up the screens. The greater the air flow around the press, the faster the ink can dry and clog. Humidity actually helps because the wetter the air, the less likely it is that inks will dry on the screen.

Press to cure

Typically, when printing with plastisol, the goal is to set the ink on the surface of the garment‘s fabric. The discharge process is different in that inks should penetrate into the garment, which means more pressure is required than with plastisol. To get adequate penetration, a sharp, 65/95/65 triple-ply dual durometer squeegee is recommended.

Our plastisol printing habits have also allowed us to stop in the middle of a print and walk away from the press for as long as needed, even overnight. Though many discharge systems have improved in this regard, it isn‘t the case with most water-based ink. For short down-times, the image area can be wiped out and placing a damp cloth on the platen with contact to the screen can keep ink from drying in the image area. But, if a job can‘t be finished in a day, the inks should typically be removed and the screen completely cleaned. Usually, the ink is then disposed of and reformulated for the next shift.

When printing with a manual, it may be helpful to flood-coat the screen after each print stroke to keep the mesh wet, helping to prevent the ink from drying and clogging in the image. For discharge printing with an automatic, set the machine to do a print then flood stroke where the flood stroke is last.

After the discharge reaction is complete—which takes place when the inks have reached 180°  while water is present—the print must reach 330° for at least one minute in order to retain color-fastness and washability. What does that mean to us? It means if we don‘t want the pigment to wash out, we may need a gas-fired dryer with significant air flow and plenty of heat or we will either be running garments through multiple times or post-pressing with a heat press.

Discharge printing has a higher misprint percentage by its very nature—more misprints—isn’t that exactly what we all need?! Many times a print problem is not detected until caught on the other end because the discharge reaction does not take place until the garment is in the dryer. That‘s 10 to 20 shirts on the belt and 10 to 20 more on the press if the catcher sees the problem. So it‘s just a pinhole, you may say? Problem is you can‘t blow out discharge ink because the dyes have been removed. It is essential to be neat and tidy and have the quality assurance working to get good discharge printing results. Fabric pens in every color are a necessity.

With any printing process, there must be sound technical criteria and usefulness for the conception and continuation of the process. The required process control and the additional cost of ink means production costs are a bit higher. However, the aesthetically-superior results of opaque colors, super soft hand and the ability to iron over the image give the printed garment a higher value, and therefore enable profit margins to be maintained or improved. The higher cost of discharge printing should be offset when applied to the resort, or any other market, for that matter. With retail stores once again entrenched and committed to soft hand prints, water-based discharge printing is back in fashion and looks to be here to stay.