It's your birthday, go wild!

 I made these slimline cards from 8x8 paper. They fit in a business size envelope - though a bit roomy from end to end. I have plenty of 8x8 paper and there's no cutting required or scraps left over - all you need to do is score and fold in half to give you a 4x8 card. 

I used some holographic paper from Dollar Tree for a framing layer and DT decorative tape inside to continue the theme.