Why most couples spend an evening on this and still reprint
The usual route is a free template, a phone editor, and an hour of fighting a crop tool so the code sits somewhere sensible. The color is nearly right. The text box will not center. Then the PDF prints slightly smaller than expected and the square ends up the size of a postage stamp on a table card.
Here the QR code on the canvas is your real event’s code, already generated, so there is nothing to paste in and nothing to break. You choose the format first — table card or A4 welcome sign — and everything else is arranged inside the shape it will actually be printed in.
Change your mind about the format halfway through and your text and colors come with you instead of collapsing. Lay out an A4 welcome sign, switch to table cards, and you have both versions of the same design in a couple of clicks.
What we would print, if it were our wedding: one A4 sign at the entrance where people are standing still, and a table card at each place setting, because that is where guests sit down and get their phones out.