A seven-band rainbow arch drawn as nested boxes, the age in the widened keystone, the unicorn standing under the arch, the details unboxed inside it.
Half an A4 sheet. Two per page if your printer can do it. Your printer will ask whether to print background graphics — say yes, or the colour is what you lose. If that is more ink than you want to spend, switch to Save ink above and the design comes back as dark type on white.
The code goes to the invitation site itself, so a guest who scans it lands on the countdown, the address and the RSVP — not on an app store.
Mateo is invented and so is his party — the QR on this sheet opens the matching sample invitation. Yours carries your child’s name and links to your own invite.