# DTG printing over screen prints?



## Sunro (Apr 19, 2008)

Hello All,

Here's a 'different' question, one I have not been able to find in this forum ... is it possible to print with DTG inks over an existing screen print? I would assume that the existing print has been made with Plastisol or an equivalent screen ink. We have a client who has requested that we overprint on existing screen printed shirts. Part of the design would be on the original cotton and part over top of the existing screened inks.

The overprint design will probably require a white underbase, but I'm not sure if there is a way to make DTG ink adhere to the already-cured Plastisol, unless flash drying first would work. Washability would likely be problematic at best.

We haven't accepted a print order yet, but the client really wants us to do it. Has anyone tried this?


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## sunnydayz (Jun 22, 2007)

I don't think you would have a problem with printing the CMYK over the print, however I don't think printing the white ink over existing ink would work. The reason is that the white dtg ink needs a pretreatment to bond to the fabric, and I am not so sure how that would work with overprinting the dtg white ink straight onto another type of ink. You could try doing a sample and see how it works, but I am thinking it would not work so great. If you do a test print, make sure to wash test it afterwards to see how it washes. 

Another issue you may have, is figuring out how to align the artwork correctly on the platen.


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## Sunro (Apr 19, 2008)

Hi BobbyLee! How are you these days?

Thanks for the suggestions. One good thing about this is that alignment shouldn't be a problem, even if we print the underbase, partly cure it, and put the shirt back in the printer.

The client wants to randomly overprint the original designs with "green" and "recycle" messages or designs. How the new image and/or lettering aligns over top of the original doesn't matter. Her idea regarding a white underbase is to have a white patch, larger than the intended new image, laid down with a fuzzy border. Then a color image would be printed roughly within the boundary created by the white patch. That should allow for lots of slop in placement.

I must admit it's an intriguing idea - er - "challenge".


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## Kornittech (Jan 5, 2009)

There is a solution for combining screen print and digital printing. The Kornit 933 can work in conjuntion with a carousel SP press.


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## Don-ColDesi (Oct 18, 2006)

My gut tells me that you may have some success direct to garment printing over water based screenprint inks but not plastisol. Kornit Guy - does the Kornit solution work over plastisol or just water based?


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## Kornittech (Jan 5, 2009)

Don, you are correct on the waterbased screen print images. These do mate perfectly with the digital inks. We will test any screenprinted samples, including plasticols, and send them back to clients for verification of adhesion.


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## bornover (Apr 10, 2008)

I have not done it myself, but I do not believe the DTG ink on top of the plastisol would stand up well when washed. Has anyone experimented with this and wash tested it yet? I am interested to know.


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## Kornittech (Jan 5, 2009)

If you have a screenprinted image that you would like to verify, we will test a digital print over the top for you and send back the results. Please just send the screenprinted sample to Kornit DIgital, 9060 N Deerbrook Trail, Brown Deer, WI 53223
We would be glad to assist.


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## Alex T (Jan 19, 2009)

We have experimented with printing on top of water based textile paint but have had little success when washing .we have pretreated some samples , others without some with white underbase some just colour ink but have never had good wash fastness.


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## Kornittech (Jan 5, 2009)

Please excuse the previous answer regarding waterbase inks. Kornit prints over a white plastisol ink base. Here is a plastisol that works well with the Kornit digital over print. 
Phthalate free PFP-VER: WH001-Aekotex Ink.
We can also print over discharge inks. The information on waterbase inks was incorrect.


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