I'd seen these on craftgawker and saved them to my (ever growing) favourites folder waiting for the right occasion... which just happened to be early in February where it was Dunc's birthday one day and my brother's the very next day!
The good thing about this is that its actually more eco friendly to make two at a time as you need a completely contrasting colour as your background (to make the image really pop), and you print out both the inner piece and the backing piece onto one sheet of A4 card - so you can just swap them over!
As I've said, the instructions are brilliant - really easy to follow and colour coded for the parts you score, and the parts you cut. I used a compass for my score lines... in retrospect something a bit smoother like a blunt edged embroidery needle would be better as I had to make sure I didn't scratch into it...
Then, its just a case of sticking this piece on to the contrasting backing piece:
I improvised the last bit by finding a spacey/roboty "happy birthday" image from Google. (I don't have lots of different fonts but obviously you could do it in this way if you did!)click here
On the post, there's also instructions for a skull pop-up and the site contains loads of brilliant other things. Thanks minieco! xx