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View Full Version : Printing white ink on dark/colour t-shirts



steve_c
06-10-2010, 12:09 PM
Hello everyone,
I had a job done recently and I was charged for two screens when printinfg in white on dark t-shirts.
Is this normal? Is one screen a base and one for making dense and more white?
Like to understand this a bit better if anyone can advise?
Cheers,
Steve

John G
06-10-2010, 12:14 PM
Hi Steve, You've answered you own question - base is printed and dried in situe (on the carousel) then the white is printed over the top. You can get away with 1 screen sometimes as you just print the white, dry it then print the white over the top instead of using a base.

Cheers John

steve_c
06-10-2010, 02:22 PM
Thanks for quick reply John.
Understand better now.
Cheers,
Steve

AJLA
06-10-2010, 06:00 PM
Interesting, unfortunately nearly all my stuff is white text on a black shirt.

John G
06-10-2010, 07:26 PM
Try the ultra opaque plastisol, you might get away with one print for thin type text but it won't be as vibrant as the xpres t'shirt vinyl.

When you first screen print white on black it looks great but after drying the black shows through and it looks off white - this is why it needs to hits.

Cheers John

AJLA
09-10-2010, 09:47 AM
We were struggling to even make our first possie as it wouldn't dry even after 24 hours until we realised it was printed on the wrong side :oops: so now we have one, yes it's black but is it dense enough..won't know till we try it will we but what I want to do next is have one make up on a lazer printer to compare the two. Unforetunately there isn't one that prints onto OHP in the town so i'll have to go into Plymouth next week then we can give the two a trial and see which performs better.

John G
09-10-2010, 10:56 AM
If the inkjet posi is black and sharp i'd just use that one - for some reason my laser printer isn't printing as dark a black as it used to but all I do is reduce the time on the lightbox to suit.

Cheers John

AJLA
09-10-2010, 11:58 AM
So a really dense black requires more time in the light box?
Will a more dense black produce a better result?

John G
09-10-2010, 12:20 PM
A dense black posi will produce better, sharper results and for t shirt work you can over expose the screen so theres less spotting out to do (small pin holes that may appear which need to be blocked out with blue filler). For fine lines, on crap posi's, I under expose which will make the lines better but more spotting out to do.

Its trial and error I'm afraid until you get the right timings - I can go anywhere between 4 and 5 mins, any less and the stencil might start washing away - any more and the stencil is hard to wash out so the light must be penatrating the black on the posi.

Can you upload a pic of your exposure unit - if its lights from above you'll be able to do a test on one screen to obtain the best timings.

Cheers john

AJLA
09-10-2010, 04:10 PM
Yep it is a light from above, I will try a get a pic on Monday for you if I can remember to get someone to bring a camera in.

It really all sounds quite daunting to me now but i suppose it's like any new process you take on.

John G
09-10-2010, 04:59 PM
OK - get some thick card, cut into strips around 30 - 40 mm wide x the length of the screen. Make a few test posi's with a lot of small text all over it - around 10 - 14pt in coreldraw and fine lines. Set it up to cover the whole screen with text and get it ready to expose then place the card strips ontop of the glass to block all the light apart from a 30mm strip. Switch your lights on and leave for around 3 mins then every minute take a strip of card off and repeat until you get to around 20 minutes - mark the screen with the minutes exposed.

The 1st part of the screen will have had the longest exposure at 20 mins then every strip will have 1 minute less. Wash the screen out and you'll see the best exposure time. The screen will probably be un-usable and need washing off but its an acurate way to get your timings right.
Simples 8-)

Cheers John

AJLA
09-10-2010, 05:12 PM
SIMPLES . . . :shock: Very clever idea which has to be done me thinks. I'll post the outcome if i'm brave enough :lol:

AJLA
11-10-2010, 04:50 PM
Hopefully going to attempt to load the image John. Have done it only once before but that was by accident!

AJLA
18-10-2010, 04:09 PM
Just to keep you posted we've prepped a few screens today and tomorrow we'll attempt to expose them.

We were wondering, as we already have most of our designs cut out in vinyl ready to press could we not use those instead of a possie ?

We have produced a few possies on the wideformat unfortunately we will probably come across a few problems with them curling in the printer so if possible to do we could start this way for our own designs.