Black protective sheath on underside of top case: necessary?

Hi,

I noticed your question awhile ago and wasn't sure what to advise (as many others probably, since this is the first answer).

I've no idea if the sheath is critical or required. I do know that if you get a new top case from Apple, it comes with a replacement sheath sticker from 3M, which is custom-cut and probably pricey to get, if you could ever find it.

Then I had an idea: why not simply use an antistatic shield bag for this purpose? The kind that sensitive electronics (e.g. cards or hard drives) are packaged in. I would simply cut out a piece large enough to mask the underside of the keyboard, and exactly the right size so it doesn't obstruct the ventilation holes.

You could even punch a few holes in it with an office hole punch if ventilation is a concern. Then attach it with insulating/antistatic tape to the top case, making sure again not to obstruct ventilation openings. (Actually, the hole punches could also serve as contact areas for attaching the tape to the top case underside).

WARNING: I've actually no idea about the electrical conductivity/capacitance/etc. properties of antistatic bags, so I'd definitely check on that first in case this might lead to more harm than good.

But if it works, you'd have a proper insulation replacement at next to no expense!

I'd be curious to hear if this is a good idea at all. Thanks & good luck!