In order for the significantly less permeable (than, say, cotton) surface of a nylon jacket to chemically bond with printed ink, a catalyst must be added to the plastisol.

The addition of nylon-printing catalyst starts a countdown—known as the catalyzed ink’s “pot life”—during which it must be used or it becomes useless.

The jacket hold-down precisely matches the outer perimeter of the printing platen in order that, along with its flexible rubber gasket, it may hold the jacket gently but firmly in place.

Though we seem to have just come out of the chill of winter and most of us have hung up the heavy coats, here in Colorado (and in many locales across the country) the nights remain cool year round, making various forms of outerwear applicable throughout the year. What’s more, if you’re not planning for the coming chill of next winter along about August, it’ll be here and you won’t be ready. Along with the changing seasons come new challenges. Jackets and outerwear are used throughout the world for everything from evening strolls in a light-weight shell to technical climbing gear.

Types of nylon fabric

Because outerwear is the most expensive apparel category, one should take special care to make sure that these products are embellished properly. Any decorating mishaps could seriously interfere with the bottom line. Nylon jackets, for example, offer a substantial value to the customer, but they’re no walk in the park for screen printers.

As garment printers, we mainly focus on Ts and sweats, usually steering customers to embroidery when it comes to decorating jackets and outerwear. However, we still end up with jacket orders that must be screen printed, either because the image does not work for embroidery or the size of the logo or the order itself makes embroidery too expensive. In this feeature, we’ll discuss nylon jackets for the most part, as they’re the most commonly printed and, according to most printers, the most challenging. Still, there’s a variety of products and techniques to help us get the job done.

There are three basic weaves that are commonly used in nylon jackets or other outerwear. The satin weave is a very lustrous fabric. This is the fabric used for satin jackets. For the screen printer, satin fabric provides a very smooth surface on which to print. Opacity and edge definition can be quite clean on this fabric. Taffeta is a plain weave and is the basic form of weaving. The yarns alternately pass over and under each other. This type of woven fabric is very stable because of its many inner-weavings, which also provides for good ink adhesion and edge definition. Oxford nylon is the basket weave of two threads over and two threads under, of a larger diameter thread than is used for taffeta. A harsher hand and rough surface are common characteristics. The rougher surface requires a thicker ink deposit. The surface of the fabric may also cause a sawtooth edge to the print.

The need for catayst

Jackets come in four basic lining configurations. The shell jacket consists of one layer of nylon with no lining. This is a lightweight style jacket or windbreaker. Of the other three, flanel lining is made of polyester, fleece is a fuzzy type of lining, and quilt lining is a two-layered fabric consisting of a batting with a nylon or poly layer. It is stitched in a variety of patterns.

The combination of nylon fabrics and linings creates a screen printing animal all its own with a distinct set of challenges. Simply getting the ink to stick to the jacket poses problems. Plastisol is formulated for cotton or blends and creates a mechanical bond to the fabric when heated to about 325°F. We cannot bring the temperature of the nylon substrate that high for fear of melting it, so the ink will not cure in the traditional way. Nor do the nylon fabrics have a tooth for that mechanical bond, so a chemical one is needed; hense, direct-print nylon ink must be mixed with a catalyst prior to printing, in order to be effective. The ink, once catalyzed, has a fairly short pot-life (up to eight hours) and must be cleaned from squeegees and screens prior to its hardening. The catalyst is available at suppliers and is comonly reffered to as Nylobond. When added in a 10 percent ratio to plastisol and allowed dry after the garment passes through a lower-temperature dryer, it should form a permanent bond with the nylon.

Linings and flashing

After the ink formulations are determined then we must deal with the jacket construction and lining. Multicolor printing on nylon is challenging. Unless the jackets are shells, they’ll have a lining which can move independently of the outer layer on press. The fabric can also shrink and move between colors as flashing is needed. Securing the jackets by tying their sleeves underneath the platen can get us through a simple one-color job, or on an unlined shell. But a jacket holddown is a must for serious jacket printers.

To address the shrinking issue you can preshrink nylon jackets by running them through a cooler dryer and/or a quick flash prior to printing. Because the ink does not penetrate the smooth surface it is nearly impossible to print wet-on-wet and a flash between colors is most likely required. When flashing between colors additional shrinking can occure.

The reasons a jacket hold-down must be used are, in general, two: to resist nylon’s tendency to shrink under heat (when flashing) and because the jacket’s shell won’t be still if only the lining is adhered to the platen.

When printing multi-colors on nylon jackets, the author recommends pre-heating each piece—either through a cooler dryer or under a flash—to minimize later heat-shrinkage.

The success of printing nylon jackets is dependent on ink-film thickness. Flashing time will vary according to the film thickness. Nylon fabric should be printed while warm, but if the fabric is printed too hot the ink may start to gel in the screen. Conversely, nylon that gets to cool can change size or shape slightly. The change will throw off registration in the print.

The flash distance should be high enough so the nylon does not scorch or melt. The entire ink film must reach temperature to achieve a full cure. The ink film adhesion will become stronger and more abrasion resistant over the next day or two.

The jacket hold-down is a very important piece of equipment, as it must hold the nylon fabric securely. Because most jackets printed are multiple-layer and lined, using adhesive on the platen as you would with a T-shirt will not hold the top layer of the garment in place. The holddown will help keep the nylon in place when flashing and printing the nylon fabric. They’re usually made of steel with a rubber cushion or gasket around the inside edges to grip the nylon fabric around the platen. A rubber pad on the platen is also useful. The rubber will help reduce the amount of heat retained by the platen.

Odds and ends

Retensionable screen frames are highly recommended for any screen-printing process, including jackets. Appropriate screen mesh is usually monofilament polyester from 125- to 305-tpi, depending on detail and color of the jacket. Nylon fabric is a hard, smooth surface, so squeegees must have a sharp, clean edge. Harder durometers such as 70- to 80- or 75-95-75 triple-ply duel-durometer squeegees are best for this application. The off-contact distance will be significant from the highest point of the nylon fabric. Quilt-lined jackets will require higher off-contact than flanel-lined products, which themselves will require more than unlined shells. Off-contact is particularly important when printing nylon that is lined, where approximately 1/16” off-contact is appropriate. Excessive off contact will requires extra squeegee pressure and can cause ink smearing.

Each jacket fabric and style poses different technical obstacles. Keeping in mind that all fabrics have their own properties is important. Natural cotton fabrics such as twill, poplin and canvas have a smoother and more stable surface that really shows off smaller text and intricate graphics and is fairly easy to print. These types of fabrics are the easiest to print on and very good results are usually obtained. Heavier textured outerwear surfaces such as polar fleece or wool don’t print all that well other than with, for example, distressed-type graphics. Some of the more technical polyester moisture management or wicking fabrics don’t have near the body or stability and pose much more difficulty. Screen printing these technical fabrics is possible, though, and small basic logos work pretty well.

The best decoration method on sports wicking fabrics is dye-sublimation. The basic fabric will need to be white (or at least very light), but completely breathable and non-disruptive embellishments are attainable through the sublimation process.

A top-notch package

Decorators seem to struggle to varying degrees with jackets and outerwear projects, more because of the pressure than anything technical or mechanical. Cranking up production and banging out three-dollar T-shirts is one thing, high-price-point jackets are clearly something different. Printers who handle jackets and outerwear usually do a fair amount of it and develop a high degree of proficiency. They understand the risk in dealing with difficult, expensive substrates. Folks that do it all the time know the tricks, and now you do to. Good thing, because outerwear offers a level of value that requires a top-notch screen printer to complete the package.