Difference-between-shirts-and-same-pretreatment-and-printing-large1

The Shirt Really Can Make A Difference In Your Finished Print

Many times white ink DTG users complain that their printed whites just don’t look like what they saw at a trade show. “It just isn’t white enough and we are doing exactly the same artwork and everything – it must be something wrong with the printer or pretreatment machine!”. There are many factors that can affect the final output of a digitally printed shirt. One of the biggest is the one you probably wouldn’t think of first.

 

Difference-between-shirts-and-same-pretreatment-and-printing-large1

Click to Enlarge

Pretreating does two basic functions for the digital printing process. The first is that pretreatment process is similar to the process of applying primer to drywall. You apply primer to drywall so the paint doesn’t soak in, and the pretreatment primers the T-Shirt for the same function.

The second function is that once the white ink is printed onto the pretreated shirt the white ink reacts with the pretreatment and it changes “state”. You can think of this state change like the flashing of white ink in screen printing. A white underbase is flashed in screen printing utilizing a heat source so that you can print a solid color on top of it so that the inks don’t “mix” and you get a crisp, clean image. When the white ink hits the pretreated shirt, the pretreatment “flashes” through a chemical reaction with the white ink allowing the CMYK that will be printed to do so on a semi-solid surface. This allows for incredible detail and no messy or blurry wet-on-wet printing.

However, when you utilize the same pretreating process, the same printing parameters and same artwork you can still get amazingly different results on your shirts. As can be seen in the photo to the left, there is a significant difference in the optical brightness and opacity of the printed garment. The only difference between the left side and the right side, and most often overlooked variable, was the brand and type of shirt printed.

The quality of the shirt is one of the biggest factors you can change to increase the quality of your finished prints. As can be seen in our illustration, the left side was printed with a Fruit of the Loom Heavy Cotton T-shirt while the right side was printed with a 100% cotton Keya brand shirt.

The tighter the weave of the shirt, the less rogue fibers straying from the thread, the better your final print (read ring-spun cotton). You can think of it as the difference between printing on regular copy paper and printing on photo quality paper off the same printer. The copy paper will print acceptably but the smoother photo quality paper will print much better. Though both printed off the same printer and pretreated the same exact way, the “photo paper quality” t-shirt will produce a much better, higher quality print.

So, the next time you are having issues with your white ink DTG prints and you want to blame the printer or the pretreatment machine, or the dog – remember to check all the variables. Utilizing the highest quality shirt, though costing a just a little more than your standard shirt you might be using, will yield up much better finished prints and more satisfied customers in the long run. For quality games, visit easyslots.com.

Weigh-Scale for pretreatment

How to Properly Weigh the Amount of Pretreatment on a DTG Shirt

How to Properly Weigh the Amount of Pretreatment on a DTG Shirt

i600_Scale 1. You must have a gram scale to do this correctly. The scale must be able to weight down to 1/10th of a gram.
Step-2-Weigh 2. After placing the rolled up shirt on the scale, tare it, or zero out the scale. This will make the shirt “weight” nothing.
Step-3-Weigh 3. After pretreating the shirt, roll the shirt back up and put it on the gram scale. This will now show you the actual grams of fluid applied to the shirt. In this example it is 19.3 grams.
Step-4-Weigh 4. Remove the shirt from the scale and measure the width and height of the spray pattern. Multiply this height x width to get a the total square inches sprayed. In this example it was 15” x 16” = 240 sq. inches.
Step-5-Weigh 5. Divide the total square inches into the total grams of fluid applied to the shirt. Here, we had: 19.3 g / 240 sq. in = .080417 g of pretreatment per square inch sprayed.
Step-6-Weigh 6. You now have a gram value of pretreatment fluid applied to each square inch of t-shirt. You can compare this to the manufacturer’s recommendations per square inch or recommended amounts for a set sprayed image size.
Step-7-Weigh 7. You can multiple this per square inch value by the total square inches recommended by the pretreatment manufacturer. If recommended is 14” x 14” area that equals 196 square inches. Here .080417 x 196 sq. in. = 15.76 grams total.
Step-8-Weigh 8. Keep a record of your pretreatment machine’s settings and the grams applied. This will help you determine when testing the best settings and recognize if something doesn’t match up you will have a history to compare current results with past history.

NOTE: The correct amount of pretreatment will vary based on the dilution of pretreatment, the shirt weight, and the color of shirt. You will most likely have to experiment with different settings and do some wash testings when first starting to learn to use your DTG printer and pretreatment machine.

DOWNLOAD THE PDF OF THIS ARTICLE HERE