discharge and pinholes

[ZooCity]

Now I heard someone mention that taping the back side of the screen accelerates the break down of the emulsion. Any truth to that?

I think that could be true. Where I tape over my marks, if the job is more than a few hundred, the tape starts to fall off. I retape with a larger piece because you can feel the moisture under where the tape was. I've had to retape two times on a 500 piece run, each time  Oi the area I'm taping to make sure I hit a moisture free area all around where the last piece of tape was. I'll try blockout next time to see how that compares, and add a random piece of tape off to the side and keep an eye on it to verify.
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that might have been me.  based on observation it seems to be true.  I do tape the underside minimally along the edges of the emulsion. 

[Frog]

My first thought is that it is not the tape that is causing the break down, but rather the collection of ink that now sits sandwiched between the tape and the emulsion.

[tonypep]

As alluded to above it is not the collection of ink but moisture. A hardened stencil should actually need to bleed moisture [/i]gently throughout the print process. The tape causes it to collect and attack the emulsion. That moisture contains trace amounts of discharge, resulting in the dreaded "tape lines".
One of the most common misconceptions is that you need to overtape. Discharge screens. While the opposite is true there are a few techniques i prefer I'll try to get to that later.

[ebscreen]

We avoid tape on print side at all costs. Short run, pinhole, maybe. We use emulsion
for any touchups, exposed in the sun and hit with hardener afterwards.

Tape on ink side works well in many cases as long as you "step" it right.

[ZooCity]

As alluded to above it is not the collection of ink but moisture. A hardened stencil should actually need to bleed moisture [/i]gently throughout the print process. The tape causes it to collect and attack the emulsion. That moisture contains trace amounts of discharge, resulting in the dreaded "tape lines".
One of the most common misconceptions is that you need to overtape. Discharge screens. While the opposite is true there are a few techniques i prefer I'll try to get to that later.

This was my gut feeling, that the screen needed to 'breathe' to hold up.  I'm still not sure what to do about it regarding flatstock though.  My screens don't breakdown but they get moist on the print side and then stick to the paper a little, sort of like when you print on a hot flashed shirt and it 'snaps' back off.  Still prints fine just not optimal.  I would imagine this is a non-issue on textiles more or less although it could explain why some can successfully print wb and disc wow and some cannot.

[mjrprint]

we have successfully shot them out BEFORE they go into the dryer, On a related note, we have washed out entire plastisol prints by cleaning it with ink degradent, came right out. . damdest thing.

I have done the same thing and it worked for me.