Ink on bottom of screen. Help!

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majorm
Posts: 2
Joined: Fri Oct 12, 2012 6:56 am

Ink on bottom of screen. Help!

Post by majorm »

Hey guys,

In need of help! I've got the exposure part down (well, pretty much) but my main issue now is the actual printing. I'm using Speedball Diazo emulsion, speedball water based ink and a 90t mesh screen. Im experimenting printing on vintage sheet music at present (i'm not going to print on shirts). I know it's not the best thing to print onto but that's not an issue at present. So I flood the screen (with little pressure) with a small rubber squeegee and print. The first couple come out ok. There are bits missing and it's a bit streaky but the detail is there. After the first couple of attempts ink starts to collect on the underside of the screen and the prints start to look like the attached image. I've tried off contact printing with a bit of contact taped to the bottom corners and I've tried on contact. No difference. I realise this is essentially for t shirts but any pointers would be really helpful as I am starting to lose my mind a little!

Cheers :)

David
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Catspit Productions
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Re: Ink on bottom of screen. Help!

Post by Catspit Productions »

Let me see if I can help some. It is difficult to diagnose these things from afar but I’ll try to assist. I would first ask how thin is this Speedball water based ink? Because I do believe a 90T mesh count would be 230 mesh here is the States so that is a decent mesh to use for printing on posters or papers.

Normally we use higher mesh counts when printing water based ink on flat smooth, non-absorbent substrates because they are most often much thinner than plastisol inks for tee shirts. So using a 230 or 90T mesh would seem to be in order. But based on the image you uploaded it looks like you are still encountering severe bleeding.

Therefore if the ink is very thin and runny to the point of being more like a dye or a stain then you may need to use even a higher mesh count with a hard squeegee. Or it may be possible to adjust your flood and stroke so as not to flood out the stencil. Perhaps you could lessen the pressure on flooding and stroking and use very light pressure to back flood.

When printing on such a substrate as this vintage sheet music we need to keep the volume of ink very low. You shouldn’t need much ink to print this paper well. Too much ink through the stencil would cause results like you seem to have.

In conclusion I can guess that the ink is either very, very thin or you are putting too much pressure into the flood and stroke. Make sure to use a very tight screen with good clean mesh and get a nice 95 durometer cut edge squeegee that is new. Those things will help you print less volumes of ink and achieve better print results.

I hope that helps out a bit. Let me know if you have further questions or comments and I’ll be happy to help in any way I can.
Jonathan Monaco
Catspit Productions, LLC
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