* cut your paper to the height you want, and twice the length
* score and fold in half
* open back up and cut two parallel lines on what will be the back of the card a little less than 1/4" apart
* cut out the center between the two lines
* punch half a circle from the open edge of the front side of the card
* cut a strip of paper about an inch wide and slightly longer than the card
* apply a large brad through the slit in the back of the card and attach to the strip...
* when the card is sealed you will be able to pull the strip with a gift card attached in and out of the center
Hope that makes sense! Give it a test run!