I found this card idea from last years stuff and I am not sure where I originally found it but I think it was on SCS. It measures 4 x 12
On the 12 inch side I scored it at 4 inches on each end. Now you have 3 sections that are 4 inch sections. Fold the middle in half in the opposite direction of the other folds. It is really simple. If you need more instruction email me.