A4 card?

https://www.tombakerofficial.com/product/whos-tom-baker-print/

What's he mean an A4 card, whats the US size of that, it's coming in a few days and I'm not sure what that is.
I looked and some places said this or that, I never trust google so please don't tell me it's my freind.

TYIA

 

Google is your friend:
A4 = 210 x 297 mm (8.3 x 11.7 in)

It's almost the same as silly "US Letter" (215.9 x 279.4 mm, 8.5 x 11.0 in) ... A4 is slightly less wide, but slightly taller.

The A and B series of paper sizes are a standard that makes sizing things easy, unlike 'US Letter" which is a weird unique size most of the world doesn't use (despite what desktop printer makers seem think with their software default settings).

 

So what US frame do I use to make it fit, do I get a matte to cover corners or something?

 

If you're making a frame, then you can just cut a piece of A4 paper to use as a size template.

 

Yeah, A4 always gives me trouble, as it sticks out above the top of my binder pages. You would want to custom cut a matte, cover some of the excess image that is larger than normal US paper, or, if need be, trim some of the photo off to make it a more standard size in the US.