Yeah it builds up.
I have one ridiculous swath of 11x17 leather that has maybe a couple of 0.75 inch open spaces left on it. I was laughing at myself the other day for moving it around when it got in the way.
This is some incentive to go and toss it.
Isn’t it funny how hard it is to even get rid of the scraps We had a water leak that caused us to pull up the floor in two rooms, including where our forge was. Good news is I’m reclaiming the space, bad news is I have to sort and throw away, and even the little scraps are hard to get rid of.
I have not yet reached this stage of letting go, and sm still hanging on to the most ridiculously honeycombed scraps. But then I tend to make really small things so I can always fit parts in somewhere. Believe it or not, I still have some untouched Proofgrade plywood, hardwood, and acrylic from the first shipment over a year ago.
May want to remove the masking and replace if you think you will use it - or wait until need to use it then mask.
I have found that masking that has been on a long time gets harder to remove. I suspect the glue sets up eventually.
Plus that PG leather with it’s painted on masking (bleh).