DTG Pretreatment Marks – What Do They Look Like and What Do They Mean?

When using DTG printing as a decoration method, there are many additional steps that are not necessarily required for traditional decoration methods (such as screen printing).  For example, many people are not aware that we must spray a liquid “pretreatment” chemical on all dark garments before they can be printed using the DTG process; this additional step is required to ensure that the white ink that is printed onto the garment does not “soak in”, literally disappearing before your very eyes.

In addition to the requirement that we must currently pretreat all dark garments, we are often asked to pretreat light garments as well (the improved color vibrancy and washability on light garments is worth the extra cost) – once again, the pretreatment liquid acts as a “barrier” to prevent the CMYK inks from soaking into the garment.  Without this pretreatment on light garments, the print would appear slightly more faded, although still acceptable (whereas dark garments literally cannot be printed without the pretreatment step).

During the curing process, the pretreatment can discolor slightly, and can sometimes leave a slightly off-white residue that may be interpreted as a stain of some sort.  This is entirely normal and should disappear with the first wash of the garment.  If you want to test it out, try wetting a clean cloth and gently wiping around the edges; you should notice that the effect is minimized, which should offer some reassurance that the first wash will indeed take care of the phenomenon.  When pretreatment is applied to certain light garments, the curing process will sometimes cause a light “yellowish” box to appear around the design – again, this is most often caused by normal discoloration of the pretreatment fluid on the garment, which should come off in the first wash.  The pretreatment residue is completely harmless (just don’t try to eat your shirt and you should be fine) and is used by any person who is using a DTG printing system; unfortunately it is simply a fact of the industry at this point.

Some garments will show an enhanced version of this effect, while other garments will show no signs of the pretreatment area at all – we try to encourage all of our clients to select garments based on:

  • How well they print
  • How well they wash after curing
  • How well they accept the pretreatment fluid
Many times our clients will prefer to provide their own garments; while this is completely acceptable, please remember that you are responsible for how your garments respond to the pretreating / printing / curing phases of the production process.

Keep an eye on our Blank Products page – we will soon be adding / enhancing our rating system for all of the products that we offer, so you will be able to quickly and easily determine which products are best for you.

(We will update this entry soon to include images of actual pretreatment marks on garments, so you know what to look for!)

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