Winston fired this volley in
:

So my intuition about an elastomer gasket
wasn't too far off then, aye?

Excellent! Thanks Lloyd.

Winston, you have mentioned the "other alternative".

Instead of holes, grommets, and bolts, some applications have a channel
frame all-round the work with a u-channel-shaped gasket capturing the
edge of the plastic sheet.

The only problem with this method for the 'ordinary' shop guy is getting
gasket and frame material that will match up with one-another and the
thickness of the plastic.

LLoyd