Can I put a backplate to a 3070 Black GPU?  Will the warranty be voided if I put a backplate?  Any recommendation where to get one?
Thanks!

It seems I need to make one then.  

Cool GTX
just have a fan blow on the back of the card
 
get a backplate if you want ... as long as you do not damage card (short or physical) not a warranty issue

Thanks for the reminder.
My casing is a Phantek Enthoo Pro.  There's a big (140mm) intake fan at the front.  That is the only intake fan of the entire pc casing. 
Well the main reason I am planning on putting a backplate is just to hide the bare circuit side of the card.  Plus to avoid the bending/warping problem.  I'm planning on using a 1/8 inch (or 1/16) aluminum sheet.  Random holes will be on it just like the 3070ti,  then I will paint it with a heat sensitive paint that changes color depending on the temperature of the card.
I know that electronic circuit boards are coated with a insulation finishing paint to avoid accidental contact (shorting of exposed contact points), but precaution is still required and a must.  The connecting screws will be my next problem.

My opinion honestly warranty should be about after change anything in the vga

Epal2Apol

yaggaz

Epal2Apol
It seems I need to make one then.  

Give this guy a look. Makes some very nice custom backplates:
https://www.jmmods.com/gpu-backplates

Thanks for the links.  Those backplates are very presentable.  Nice price too.  It is something to think about, for me, the prices are 1/10th of the GPU's MSRP.  But it is really stunning to have one.  I know it will be a conversation starter.  Now I am confused.

Not sure I would use those backplates. They look really great and all, but they are acrylic. I would think the heat of the card when gaming would be enough to cause the plate to warp or deform. Also, being acrylic, it would not dissipate any heat from card. Instead, I think it would somewhat insulate it. I would only use metal with stand-offs/thermal padding for a backplate for best temps. I could be wrong about using acylic for a backplate, but I would research it first.


Another thing to consider with these backplates is the thickness (1/4"). I dont think I could use one of those with my ROG Strix Z490-A mobo. I have a SB AE-5plus sound card installed in very top PCI-E slot above GPU. With a jmmods backplate (1/4"), there wouldnt be any clearance between the 2 cards with my config. The cards would be 'wedged' into their slots...... if I could even get them in. The EK backplate I have on my RTX3070 is almost too thick. Maybe 1mm clearance. Not the greatest config using the top PCI-E slot, but the case (O11 Dynamic) and bottom radiator (UT60) prevent me from using any slots below the GPU.