Clear or black underbase

[Wildcard]

I've had some issues with registration while printing the attached job. The image shows a clean back print without issue btw on a large tee.

The lines in the art are fine enough that I only used a 0.25pt trap (0.5pt stroke) for my underbase, otherwise there was not much to put down. And I've struggled with the lines being very unforgiving with any slight registration issues between ub and top white.

My solution to get the first few looking right was to run the top white screen around the auto twice. Obviously not ideal so I'm hoping for a solution that is more forgiving of my registration woes. I have 2 ideas:

Print a clear ub, or possibly a black ub if only on black tees? This way if the ub registration isn't spot on perfect in some area of the print it should still look ok.

Or remake the underbase screen to only underbase the text and possibly the solid areas that can take a bigger trap?

Any recommendations for tricky underbases?

[Doug S]

If discharge isn't an option, I like your second idea better to make the lettering and larger areas more opaque.  The little fine lines wouldn't be a problem visibly to not be 100% white imho.

[tonypep]

Another option is a gray barrier base. Rutland and others have these products

[Gilligan]

Are you choking the underbase that is going under the top white?

[Frog]

Are you choking the underbase that is going under the top white?

"...The lines in the art are fine enough that I only used a 0.25pt trap (0.5pt stroke) for my underbase"

[Prince Art]

If it's a short run, I'd just p-f-p the top white, rather than redo art.

If it's longer, and it's on 100% cotton, I agree with Doug - your idea of using one hit on detail, top white on big areas has worked well for me.

I wouldn't discount what tonypep says, either. And if you're printing on a poly blend, that could be the better way to go. (I haven't tried it, though. We only recently tried a blocker black UL for poly, which still required white UL + top white.)

[Gilligan]

Are you choking the underbase that is going under the top white?

"...The lines in the art are fine enough that I only used a 0.25pt trap (0.5pt stroke) for my underbase"

Right... but I learned a while back (thanks to you guys) not to trap white on white.

[1964GN]

We never choke white on white. On runs over 60 or so pieces (no halftones) we print to identical white screens P/F/P. Less than 60-ish we go around twice. An image with halftones we might have one screen with all data and one with just the 100% white areas.

[Wildcard]

Not sure I've ever received or read the advice to never trap/choke white on white, but I'm happy to take that on board. Does this require pinpoint registration to work (meaning from the machine, not setup)? For instance in this run I started with the ub and top perfect and it drifted slightly out of reg after around 80 prints. I'm thinking its an issue that the micros have too much play in them to hold perfectly, but this design with the vertical lines shows the reg issue very boldly where most designs wouldn't.

The job is 450 cotton tees, 200 cotton hoodies and 400 singlets/tanks, so getting an ub solution working is important. Discharge not an option because of my dryer setup.

[Gilligan]

The way I explained it to my guy (who was being stubborn about the issue) was:

If you don't choke and your registration gets off a bit, the underbase will peak out and you will see a bit of only one hit of white.
If you DO choke then even when you have PERFECT registration, you see that outline of one hit of white on EVERY edge.

It's better to not choke and occasionally be off than it is to choke and be off EVERY time by design.

[Inkworks]

Lil' run, PFP 1 screen, bigger run, burn the same film twice.  You need to be able to do them on your press with near perfect reg. if you can't, get your press leveled/calibrated.

[Wildcard]

Lil' run, PFP 1 screen, bigger run, burn the same film twice.  You need to be able to do them on your press with near perfect reg. if you can't, get your press leveled/calibrated.

Sigh... Yes calibration is definitely needed.

[1964GN]

If your press doesn't hold registration then you have more important issues to address

[Wildcard]

If your press doesn't hold registration then you have more important issues to address

That is true, but it helps to have a few workaround tricks in the bag to use on jobs like this that show off minor problems.