Noobian w/a few questions.. (Off-contact, Registration..)

Hey there people. So I've only recently started printing posters (t-shirts for a few years), and have had a few bumps so far. I'm sure there will be many more to come, but here are a few questions I'm still unclear about. So far I've built a 4x4' vacuum table (everything's bigger in TX?) w/a foot pedal, using 230 mesh 30x40 screens (manually), using Speedball Acrylic inks..

1. Can too much off contact cause a print to bleed out? I had a tiny 2 letter print to do, and had a hell of a time getting it to come out clear. Black ink, 3" normal durometer (70?) squeegee. I noticed if I flooded the image too hard after the print, it was a definite mess the next time around. But it was just super inconsistent. One pull would be fine, the next, a blobby mess. Put masking tape on the print side and peeled off a couple times between prints to get the excess off, then tried again. Finally wound up removing the quarters I was using for extra off contact and this seemed to help, a little. Any ideas? I had put them there because my 1st print had too little off contact, and the paper kept sticking to the screen after my pull..

2. Registration. Using DYMO Embossing tape to create an upper left "L" and a lower left "L" for registration. It seems to be fairly accurate, but not as exact as when I use my t-shirt press, obviously. I'm a perfectionist, so it's really hard to just accept 'ballpark' registration. I know some artwork does not need to be perfect, but then I see some Flatstock shit that makes my brain crawl. Looks like perfect damn registration. I want to eventually offer damn good prints to my customers, w/very little inconsistencies. Do I need to just suck it up and keep practicing, or is this something I just need to get used to? Or is there something I'm missing? Is there any tape that's thicker than this DYMO one?

3. Registration between colors. Right now, I print one poster w/the 1st color, then do the whole run of that color. Then I re-position the original poster in my "L's", bring the 2nd screen over, eyeball the registration over that print, then clamp it down into place. Is that the normal way to register between colors?

Those are the biggies for now. I really appreciate any tips or feedback..

Alan

(pic of the blobby mess)
http://img854.imageshack.us/img854/9994/85148279.jpg

I don't have as much experience as many others here, but this is my take on it:

1. I would try a harder durometer squeegee, 70 seems a little too light for paper, especially since you describe a lot of off-contact. That extra pressure from pushing your screen down is going to bend your squeegee more than usual, which puts down more ink, you lose the hard edge of the squeegee a bit, and it blobs out under your screen. Check the angle you're holding your squeegee at, you could also be flooding too hard or more than you need to.

2. The two-L system you're describing is probably at fault. I think generally a registration system with 3 separate points is considered the most accurate/consistent. Try two separate "bumpers" along the long side of the paper and one on the short, and make sure throughout the run you always register to those sides of the paper (which is sounds like you're doing anyway), so if there are small inconsistencies in sheet size, it doesn't throw off your registration.

3. That doesn't seem out of the ordinary. Eyeball it, do a couple test prints. Double check once you've clamped the screen that you haven't moved it slightly. Also, good register marks and trapped artwork make things go more smoothly.

probably way too much lift (at the back?) and if it is a small squeegee, you are probably folding it over/have a bad angle.

what mesh? too open (under 200) and you would have a tendency to bleed out.

try not flooding next time this happens. At least to print it out. Your flood should be one time, thin. dont's let ink dribble back over the image.

Re register, one corner, and one side - same corner and side for each additional colour. Put this in front of you so it's easy to place the paper.

when you do the second colour, lock the screen in and then move the print around (with posi taped in place) until it lines up, then put your tabs down. Be prepared to move the register tabs once you start printing, it takes a few prints to get it lined up.

If you are just hinging you screen in a couple of clamps, make sure they are screwed tight, and make sure your screen is locked in. Place 2 blocks of wood on either side of the front of your screen and clamp them to the table, this gives you guides to hold the front of the screen from moving.

Print in the same direction, with the same pressure. using screens with the same tension will help too.

last...make sure you place the paper consistently and carefully in the guides, for every colour and every print.

ok, enough from the Canuckistanis.

Sweet, thanks redbank. i'll order a couple triple durometer sqeegees (from Ryonet?) and give those a try. I'll also try the 3 tape points w/the bumpers and see if it works any better.. Appreciate it.

thanks andy. yup, too much lift at the back for sure. the mesh wash 230, so it shouldn't have been the problem.

i'll try the two pieces of wood along the screen for top registration..

thanks!

I had a similar problem: in my case it was an emulsion just too old, with had improper coherence with the surface and caused bleeding, getting worse on each pass. just my 2 cents :-)

One more obvious thing is the ink consistency, it the ink is too runny it may have to be thickened up. The more off contact the less runny it should print but anyways good luck trouble shooting. . .