Digital Decorating:

DTG the Right Way

By Terry Combs, Contributing Writer

January 19, 2016

Decorators usually love attending industry trade shows because of the bevy of educational and networking opportunities they present and the chance to meet with their suppliers — all under one roof.

But another benefit of visiting with exhibitors — particularly equipment manufacturers — is seeing the graphic output they can achieve with their machines, regardless of whether it’s a screen-printing press or direct-to-garment (DTG) printer, on different substrates. Regarding the latter, it’s safe to assume the DTG samples being printed are optimal files and the substrates (shirts) are the best for the process.

But let’s say you decide to invest in a DTG printer that achieved pristine results on the trade show floor, but not at your shop. Rest easy; your vendor didn’t trick you with smoke and mirrors.

However, there are a few things you need to know to achieve that same high-quality image away from the trade show.

The Right Shirt
The ideal garment for the DTG process is one made of 100% ring-spun cotton. The water-based inks used in all DTG machines are specifically formulated to bond with cotton fabric. More tightly woven T-shirts and other garments will accept ink better than those with a loose weave.

Some garment brands will print better than others, so remember to conduct tests on different brands or styles before you begin production. Inform your garment suppliers that DTG printing will be your decoration method and ask for their recommendations.

Variations among garments also can impact your ability to do contract work. While common in screen printing, the contract option is not as easily accomplished unless you, the printer, specify the garment brands you will allow and your customer is willing to buy the right garments.

You also can print blended fabrics. The higher the cotton content in your garment of choice, the better your finished print will be. For example, it is difficult to find 100% cotton sweat shirts and hoodies in today’s market, but 90% cotton/10% polyester or 80% cotton/20% polyester are readily available and print perfectly fine. You can get a respectable print on a 50/50 garment, but the image will never be as bright as on 100% cotton, nor will it wash as well.

The Proper Art File
Regardless of decoration method, customer-supplied artwork always will be the most difficult step in the printer/customer relationship. With no instruction from you, customers tend to provide very low-resolution files. Sometimes, it’s simply a matter of asking for the proper resolution and format, since few of our customers know exactly what we need to print the best graphic.

Ideally, this should be a 300dpi file saved at the full size at which it will be printed on the garment. Many customers will want to give you a JPEG file since it probably is the most common, but this file type limits your ability to manipulate it, if necessary. Specify to your customer that you need a PNG, PSD or EPS file, saved with a transparent background, for best results.

Use the art program with which you’re most comfortable. The most common programs in garment printing are CorelDRAW, Adobe Photoshop and Adobe Illustrator. Since DTG machines can offer photographic reproduction, the latter is the most popular.

Consistent Pretreating
Decorators who struggle with a DTG image usually cite problems with the ink, but that’s never the case. Most of the time, the problem stems from something else the operator is doing incorrectly.

The primary variable that most DTG decorators don’t control sufficiently is applying pretreatment solution — a requirement for white-ink printing — to the shirt. Two things happen with this type of decoration when you experience issues on dark shirts: Either the print looks dull or it has washability issues.

Getting optimal results takes a little practice in this area. When you change garments or brands, do more testing with the pretreatment application. That means a little bit of spoilage and time spent honing your craft.

Using an automatic pretreatment machine will result in consistency from shirt to shirt, but a handheld power paint sprayer is a good alternative. Paint rollers, pump spray bottles and similar hobbyist application methods will result in inconsistent application.

Also, remember that time is not much of a factor. It is totally acceptable to pretreat garments weeks ahead of time with no ill effects. Just remember to heat press stored garments for a few seconds before printing in order to remove wrinkles and lay down the fibers on the fabric surface for the best outcome.

If a printed graphic looks dull or not fully opaque, first investigate whether too little pretreatment solution was applied. Experiment with varying amounts and take notes. You also may see dull areas through part of the image. This likely is from uneven application of the pretreatment solution.

If the garment has the stiff, box-shaped outline from the heat press, it means you applied to much pretreatment solution. Doing so also can cause ink washout issues, since the ink may be on top of a film of dried solution rather than bonding to the fabric.

Once you get the pretreatment process dialed in — and it may take a little trial and error — your prints will jump off the garment, just like at a trade show.

More Or Less Pressure
In the last step, another variable causing a dull and washed-out appearance is heat-press pressure.

Too much pressure can result in the color ink on top and white ink below blending together and muting the image. Heavy pressure also can press the ink into the fabric, thus dulling its appearance.

Backing off and lightening the pressure on your heat press will allow your finished print to have the same bright appearance as it did before curing.

The vendors at trade shows are not performing magic when they print sample shirts for you. It’s simply a matter of choosing the right shirt, pretreating it properly, printing the best high-resolution file and curing the finished print adequately.

A 35-plus-year veteran of the garment-printing industry, Terry Combs has managed production shops large and small across the United States. He currently does sales and training with Equipment Zone, Franklin Lakes, N.J. For more information or to comment on this article, contact Terry through his website: