Assuming you talk about a paper-ringbook-type of thing to write on with a pen, you could buy the ones where the last page is made of cardboard to prevent bending. These sizes also come as books, hardcover thing with blank pages inside, hard to bend.

If we talk about an electronic device, just please dont sit on it ;)

OP wrote “A6” so the thing in question is the size of a postcard and OP might be European.