Edited to add: Yapha Mason greatly simplified the instructions HERE. Thanks, Yapha!
For the purposes of this tutorial, I will be drawing heavy lines with a Sharpie, so they can be easily seen in the photos, but you will be drawing light ones with a pencil and erasing later.
Supplies you will need:
- 10" x 10" lightweight cardstock, like Designer Series Paper
- Stampin' Up! grid paper (102787), or a grid mat
- Bone Folder (102300)
- Sharp pencil and eraser
- Ruler (quilter's ruler works great)
- Paper Cutter (104152) with cutting and scoring blades
2) Lay cardstock on grid, having edges even with lines, then draw a light guide line down 1½" from original pencil mark, using the ruler to make sure the line is perpendicular to top edge. (Ruler should be on the same grid line at top and bottom of paper.)
3) Now draw an angled 10" line from the lower right corner to intersect the guide line. Have the end of ruler at the lower right corner of your cardstock, and rotate to make the 10" mark on the ruler intersect the guide line. Making sure the ruler hasn't shifted, draw a light pencil line from guide line to corner. Repeat for the left side.
4) Place cardstock in Paper Cutter with 10" pencil line exactly centered over cutting groove. (You can lightly slide the blade without pushing and cutting to check that the center of the blade is going to follow your pencil line.) If it lines up properly, go ahead and cut from one end of the paper to the other.
5) Repeat for the other line. You should now have a 10" equilateral triangle, and the hard part is done!
6) On each 10" side, make a pencil mark at the halfway point, 5" from each end.
7) Using the scoring blade in the Paper Cutter, lightly score between the marks. (Yes, I know the cardstock is different in this pic. It's from the completed sample at the top. I forgot to take a picture of the turquoise shtuff.)
8) Fold up one flap and place crease under the 1½" mark on the ruler. Use edge of ruler to form new flap, folded back. Flatten with bone folder. (Note: If your ruler isn't the 2" wide quilters style, use the grid paper instead. Have the fold on a grid line, count 6 squares up = 1½" and place ruler there.) Repeat for other sides.
9) That's it, just decorate and you're done! To close the star, fold the flaps in, like folding flaps on a box top. The last one gets tucked under the first.
Have fun making these!