Mark folds on both edges: On front of paper, mark 1/2 inch from top. Then, mark every 7 inches.
Line up ruler with each set of marks; score across paper with bone folder.
For back, measure 4 inches from top, then every 7 inches; score.
Fold at each score line, bending it toward indentation. Unfold end flaps. Punch holes in bottom corners.
Thread ribbon through, and knot ends; trim. Set cards in creases.
43-by-7-inch pieces of card stock for each stand
1/4-inch hole punch
Two 26-inch pieces of 9mm ribbon
Six 6 1/4-by-4 1/4-inch note cards
Make simple rectangular tags on a computer (ours have coral-color words and aqua borders). For notched corners, clip with a 1/4-inch hole punch. Apply an adhesive dot to the shell's flattest part; it's removed easily, so guests can have their shells to take home.
One stand will hold six cards and stretch to about 25 inches. If you want a shorter one, subtract 7 inches from card-stock length for one fewer space.