[dopamine36]

Hey all, been using my FreeJet for a few months now and I just can't seem to dial in the settings to get dark colors saturated over a white underbase when printing on black or color tees. Wondering if anyone has any tried and true settings for these jobs. (printing sample here) Things I have tried:
- Lowering white underbase to as low as 95%
- Hovering heat press over finished design without curing sheet for 10-15 seconds
- Varying curing times
- More/less pretreatment

What I'm using:
- FreeJet 330TX
- DirectInk inks (DuPont)
- DirectInk dark garment pretreatment
- DirectRip software
- HotTronix heat press
- Wagner paint gun for pretreat

I haven't experimented with drastically lowering the underbase % to say 50 or 60%. Thanks for your help!

 

[ghostofmedusa]

Hey Travis. Said (Sah-yeed) at Omni showed me the best trick ever for this little issue that effects all DTG's alike. Since Black is the main color that the WUB (White Underbase) finds it's way through during heat press phase... No need to mess with lowering WUB percentages or anything else for that matter

Lets say you are printing on a bright Yellow Tee...
1.) Set RIP to print as if on a Black T. (This way it will not print WUB under any thing black in the image)
2.) Turn off your second CMYK pass, set passes to "Zero"
3.) Once that first WUB pass is complete, go back and tell Kothari you are printing on a White Tee for a unrelated 2nd pass.. All you have to do here is remember the distance/ inches the image is from the neck, as Kothari will reset that parameter to "zero" once the first pass is complete. (ex: if distance was 2" from neck on WUB pass, then enter in 2" for the CMYK pass on the "White" T print.) This will only deliver the Black ink where the White ink is absent, leaving you with a solid black. You don't have to hover either, just press for 3 minutes like the usual colored Tee press prescription and your finished product will be free of any WUB bleed through.
*The other colors don't seem to be affected by WUB much... Just black

It may seem a little involved, but its not too bad at all. Adds about 2 more minutes to the process. Just remember to re-input the image distance from neck line, as it will get erased after WUB pass is complete. This fixes that issue right up, and the image washes excellent. So to recap - 2 separate print jobs to complete 1 finished Tee. 1st WUB on a black Tee, then go back and do a brand new job on a white Tee with that same image you have open.

Hope this helps

 

[dopamine36]

Ah yes! That would definitely work, as it is predominantly black that's affected. I will definitely use this tactic when needing those saturated blacks. Said and Jose at Omni always have great tips!

Out of curiosity, have you experimented with turning down the underbase? If so, how low have you gone and with what effect?

 

[ghostofmedusa]

I have tinkered with it. For me, turning down the white any given amount was akin to going from 1440x1440 to 1440x720, or down to 720x720 etc... Those settings that Victor made in Kothari are good enough that all one really needs to do is change resolution to affect how much white gets laid down. And it all boils down to how much thick Titanium-infused White ink will live underneath the very thin CMYK (mostly Black) layer on ink on top. I like to think about it like this:

I like making pizza. If I put too much red sauce/base down, it will most likely bleed through the cheese layer and overpower the cheese flavor. So I would have to get just the right amount of evenly spread sauce onto the dough before I lay the cheese down.... That make sense? I dunno, maybe I'm just hungry for pizza.

 

[dopamine36]

I like to think about it like this:

I like making pizza. If I put too much red sauce/base down, it will most likely bleed through the cheese layer and overpower the cheese flavor. So I would have to get just the right amount of evenly spread sauce onto the dough before I lay the cheese down.... That make sense? I dunno, maybe I'm just hungry for pizza.

The 'pizza' analogy works well. It's good to know that lowering the resolution of the white underbase layer would have a better effect. Now that I've had my FreeJet 330 for a few months I have a greater understanding of the mechanics of it all. Before, I would have been worried that 'lowering the resolution' would produce a fuzzier image, not just use less ink. The OmniPrint team have been great to answer my questions with pretty much every new job I do haha.

 

[xtylcom]

Said told me about the two step process. It worked so well that, although the customer had already signed off on the previous prints, they insisted on having the two step process instead. So, I lost money on that job but learned a very valuable lesson. And YES watch the margins!