What you will need:
-Ribbon, about 2 spools or 6 yards
-4 Fabric Quarters
-Iron on Hem Tape
First, I went to Michaels and purchased a couple spools of brown & white polka dot ribbon to use on the vases and other decor for the party. With the two leftover spools, I used the ribbon for the top "string" of the banners. I already had some Hem 'N Bond at my house, so I used that to hold everything together.
I also went to Joann's and purchased a few "Fabric Quarters" in coordinating colors. These are the perfect amount of material, and only cost $1.50 each! I took the cardboard out of one of the fabrics and cut a simple equilateral triangle. I just eyeballed it, no measuring necessary, unless you are really anal about it.
Next, I simply doubled the fabric and laid it out on the table, so that I could cut twice as many triangles at a time.I placed the cardboard triangle in the corner, and simply cut along the edge. The thickness of the cardboard serves as a good guide, and a sharp pair of fabric scissors also help a lot.
As you can see from the above photo, it actually was the perfect size triangle because it fit evenly going across the fabric. I did not have any leftover fabric! Continue this until the desired number of triangles are cut. I believe I cut around 30 of each, and I probably used about 20 of each. At the end, you will have a ton of little triangles:
Notice I also did not iron the fabric before I cut- oops!! Usually this would be good to do, but I cut them pretty evenly, and the polished cotton I was using does not have any stretch, which would cause them to be different sizes after cutting. I just figured I would do all the ironing at once.
Set your iron for Medium heat, or according to the instructions to the Heat 'N Bond. I have the multi-pack, so it had a thin tape that was smaller than the ribbon.
I pre-cut the ribbon in desired lengths by first stringing them up on the doors and walls where they would go for the party. Then, I laid the ribbon, polka dot side down, on the ironing board and placed the hem tape on the back of it. The tape is double sided, so DO NOT IRON the hem tape to the ribbon without the triangles on. It will burn the iron and melt the tape.
At this point, before I ironed the hem tape, I quickly ran over the triangles with the iron. (please forgive the dark pictures, as it was 9PM and I didn't feel like adding light just to make the photo better).
After the triangles are individually ironed, take one and starting at one end of the ribbon, place the triangle, pattern side down, along the edge.
Continue to put the triangles along the ribbon, with the hem tape between, alternating colors. Since I had 4 patterns, I would iron after laying out those 4 triangles.
Place the iron on each triangle edge for about 10 seconds, or according to the Hem Tape packaging. Be sure to not touch the iron to the hem tape where you have yet to place triangles, as it will melt and you will need a new piece of hem tape.
Continue this until you get to the end of your ribbon piece. If you have a little leftover ribbon at the end, and not enough room for a triangle, simply trim the ribbon. Voila! You have made a banner. Here is a look at mine again (in the living room and in the dining room):
And in the living room (again). They are not perfect, but they literally took me an hour and a half to make all 3. The cutting of the triangles took the most time, and putting it all together is easy peasy.
If you want to get really fancy, you could make them double sided, or actually sew them. But I wanted to keep things quick and simple, and guests didn't really inspect them anyway. I will definitely be using this decor for a party again soon!