ink going through to other side of shirt

Dont know about pressing too hard...but the back of the shirt should be on the other side of the platten when you print.

is there a way to stop it from going through to the inside?

Sounds like you're using too much squeegee pressure.

Auto or manual press?

What kind of garment, lightweight?

What kind of ink, plastisol, water base?

Did you thin the plastisol?

What mesh screen?

It's usually a case of too much pressure, but I just printed a job on some Gildan 5000G (the 5.3 oz. ones), print/flash/print, and the ink was going all the way through to the platen, and I wasn't using a lot of pressure. I think some of these shirts are getting crappier by the day. Even the Gildan 2000's seem to be a tad more sheer than they were a few years ago.

correct me if im wrong, but there are a lot of factors to that scenario. for example, im a newbie to screen printing. i did my shirt and it turned out jus like yours, the ink passing thru the shirt. after "analysing" and understanding the whole process, i found out

1. i was pushing too much ink
2. i need a more thicker ink
3. or i need a finer mesh.

so wat i did to rectify it was, make sure u have enough ink and do 1 pass on the shirt without flooding. i know it may sound weird but it works!! for me at least. no more bleeding around the design nor passing thru the garment. then do a back pass to prepare for the other shirt.

hope that helps a little