Very interesting....Something else to test!

If the fuse blows for safety reasons and that stuff is semi-conductive, you're in for a much more miserable time than the cost of replacing that fuse.

Just read a bit more into Graphene that used in G Shield. l think your correct John,although it's metal free, l believe it will Conduct power,this is Tony's department really.
lf you where going to apply,it would need to be sheilded,over the glass, then apply a G Shield painted paper sticker on top, thats a lot of messing around, l will try it on my DAC fuse, l'm on the fence on this one.

Rustins G-Shield is a high-quality water-borne paint designed to reduce hum/buzz and electrical interference [in electric guitars].

G Shield can be applied with any brush to the pickup and control cavities in electric guitar/bass to reduce hum and noise.

It can also be used as conductive paint/paste or ink to make electrically conductive circuits, including switches and for RF/EMI shielding and screening.

G-Shield is solvent free with low emissions and has lasting corrosion resistance as the paint contains no metal particles, the carbon in the paint prevents the formation of corrosion on metal surfaces. Can be applied under all commonly used emulsion paints and clean organic plasters. G-Shield has incremental shielding attenuation (up to -57 dB for one layer of coating) for the frequency range up to 20 GHz and higher, including the 5G frequency spectrum

• Contains Graphite
• Breathable, low-emissions, solvent-free
• Lasting corrosion resistance, contains no metal
• Can be applied over all commonly used emulsion paints
• Reduces hum and electrical buzz

www.northwestguitars.co.uk/g-shield-emi-shielding-paint-125ml/

The best-known method of shielding control/pickup cavities in electric guitars utilioses copper tape.

Excellent advice John

Interesting tests, Rustins doesn't seem to block lower frequencies like LW or MW, but l think it's done to thickness on low frequencies, will test on FM next,we know it works on Wi Fi and 4G.

So l took the plunge and treated the fuse in the DAC,it was a Gold Plated ,Bussman, l put a pre painted sticker around back of plug, surprisingly a little bit more insight,a little bit holographic,so thats a keeper, they all add up.

Next, out comes the box, l placed the leaf audio device inside, excellent, slightly less harshness, better definition.
So on the the I2s cable and Black Magic USB, out comes the Copper tape and remove the box...Excellent,similar to the box, but still retaining a little harshness, looks like its worth sheilding this unit.

l have a bit of a issue of painting the inside of a unit, simply even when the paints dry,the graphine comes off on to your hands...not good, almost like when you handle coal.l guess a coat of emulsion or clear lacquer would work, or apply some insulation tape over the top.
What l can say G sheild,is as effective as copper tape, and comes into it's own, when you want to splash it all over like aftershave, will look into some sealant next, hopefully it should stop it rubbing off.

Just thought I would add a small bit info ref testing with the G Sheild, as I discovered it is pretty ineffective on LW MW radio band, you can test this theory with a portable radio, try and find a station that is around the half way mark signal wise, turn volume up! Place inside box fully closed,if you can no longer hear the signal, the sheilding working, but as stated it won't on the LW & MW bands, this is down to what as known as the Skin Effect.

So whats the point of G Sheild, well when you start to move to higher frequencies, thats when G Sheild, or Copper or other metals starts to work.

Now unless you have a portable Short Wave radio or a SDR reciever, you won't be able to test this, I managed to get G Shield working at 6060 Mhz listening to China Radio International, good signal, once in the box, signal gone. Due to shortwave being quiet these days, I didn't venture to the 4MHz band, but from 6mhz all the way up to 30Mhz it worked.
I then tested the FM band 107.2 MHz and again it worked. We already know that it works on the WI FI Band 2.4Ghz and 4G 800Mhz (O2 UK) from my earlier tests.
Of course, these are basic tests,anyone can conduct, and no doubt you could go really deep into this, but I hopeing that my simple methods I have used, will also help others.

Keep us posted

Possiblely, but you run the risk of keeping the noise inside the sheild, l guess it depends on what your using it on.
l was considering using something like this for my NUC.l believe you can get a copper version as well.
Interesting, l had a look at the photos on Amazon, the claim frequencies it reduces confirms my tests.

Thanks Martin, yes aware of this,it will probably be a small tent,l don't think the fabric is air tight, but need to do a bit more research