Need help with red shirt pretreating and printing (DTG kiosk)
Hi - newbie here. Our first job with our brand new DTG Kiosk is for red shirts. Not the smartest idea, but it was a request from my daughter's school (and it would pay the first month's rental!).
We've got the printer set up, we've got the shirts, we've got the designs. Now -- how do we pre-treat them (or do we). We tried printing on a red shirt without any treatment and the white ink, which we do need, just went away.
Any and all help and advice will be much appreciated.
Re: Need help with red shirt pretreating and printing (DTG kiosk)
You really can't pre-treat red T-shirts. I speak from the experience of having worked with some very large garment manufactures both here in the United States and overseas.
There are folks who will guess that you can and some that will state that you can pre-treat them like it is a fact, but the truth is - you can't. The most common urban myth is that you can run them through the dryer several times to build up the heat and 'set' the ink. This is simply not true.
Red shirts are normally over dyed items and are not fully heat set for aesthetics. In order for the manufacturer to properly heat set the majority of the red dyes to the material, the shirt would be a dark blood red color and would not be preferable to most consumers.
On a 100-percent cotton shirt, the dyes will not be completely heat set and will leach back into the wet ink when any heat is applied. On a combination polyester/cotton shirt, the dyes will simply set on the polyester thread, which they cannot penetrate, until the heat is applied. When heat is applied to the dyes they turn to a liquid again and leach up into the white ink to turn it pink, then red.
Screenprinters, taking a pointer from sign painters of old, often print a thin barrier coat of silver first, gel this layer and then print a layer of white on the surface. It does not always work.
Look, just because a shirt exist on the market, doesn't mean that it IS printable. Some just won't be and you will need to substitute or not take the job.
Re: Need help with red shirt pretreating and printing (DTG kiosk)
I agree with most of what Bill said. It is a challenge to print red shirts. However, we printed a round of red shirts for our shop uniforms, and were able to do so successfully. We used 50/50 PT on 100% cotton T's (gildan ultra I believe) and it worked ok. We specifically built the design to have no white in the finished print, so that helped. Also we only had to do a small run of 6.
I am going to see if I have any red shirts laying around and run a test print with white in the finished image. If I find one I will post up results and pics. (good or bad)
edit - It will certainly not work on any blend. Polyester will allow the dye to migrate.
Re: Need help with red shirt pretreating and printing (DTG kiosk)
Don't forget a few things.
1. If you don't apply enough heat to the ink, it ain't cured and will come off in the laundry. Make sure that ink reaches the proper temperature, usually 320 degrees throughout the ink layer. Since the dyes will be activated at about 180 degrees you should see some red in the smoke at 320 degrees.
2. Don't forget to do wash tests on the shirts after you screenprint them to assure that the inks are properly cured.
3. Be aware that even if the ink is cured, when laundering the red shirts that the dyes will be released with heat in the laundry. Once they are released into the laundry water, then the ink will be heated as well and will open up allowing the red laundry water to leach into the now soft ink.
Re: Need help with red shirt pretreating and printing (DTG kiosk)
Thanks for the guidance so far.
1. We do have a heat press, we'll pay close attention to your advice about timing and temps.
2. 50/50 PT means a 50% dilution of the pre-treatment?
3. Are we supposed to wash test a single shirt or each one?
4. Should we try to make sure that if there is white in the design, that it's not really white (in other words, should our white dove be more of a cream color?)?
Re: Need help with red shirt pretreating and printing (DTG kiosk)
I have to ask, why is it that anyone can think that they are reproduce the same job over space and without any real verifiable set of standards. Look are you using the same brand of shirt from the same dye lot? Are you using the same machine set to the same specifications? Are you using the same inks? Are you washing in the same hardness of water, at the same temperature, etc., etc.?
Gee, did we really prove anything? Well, maybe something. Is this really something? Well, sure it is!
Re: Need help with red shirt pretreating and printing (DTG kiosk)
Quote:
Originally Posted by binki
... except they turn everything else red in the wash!
And now I have an understanding why this happens.....
Being an engineer...I like knowing why things happen sometimes.
__________________ Big Daddy Screenprinting -Affordable contract Heat Press Services & Low Volume Screen Printing up to 4 spot colors with no setup or screen fees
Re: Need help with red shirt pretreating and printing (DTG kiosk)
Many many thanks to Printzilla for his advice and examples. We're modifying our design to use a 2-pass black instead of white plus color passes until we're better at it (spent quite a while and lots of ink yesterday).
Just one last question -- do we wash test each shirt or just one from each batch? (3 batches for this customer, one batch for each design)
Re: Need help with red shirt pretreating and printing (DTG kiosk)
Just one shirt. No need to wash all the shirts. Include it in the order as an extra. We do it as a way to show the customer that the order has been quality controlled. Then they also know what to expect.
Also, if you have not already, you should have wash examples of a white, light, medium, and black shirt on display, so customers know what to expect. I would suggest an example of each at no washes, 1 wash, 5 washes, and 10 washes. A total of 16 display shirts.
Need help with red shirt pretreating and printing (DTG kiosk) 
