Before we can get to the myriad ways to hang a banner we'll need to start with the surface material. I use a medium-to-heavy weight Roclon* sold by the yard.
You can cut out your finished banner shape before you begin or wait until everything is complete before trimming. I prefer to paint my design first so I can adjust the final parameters if needed. If you are not a painter you can wet mount fabric or other materials on the banner using this method.

You'll notice throughout the series that I usually emboss the tabs or flap to add interest. You can create this effect using the method shown here.
Once the banner design is complete, refer to the series suggestions to select the manner of display, then trim as desired and apply a finish to both sides to prevent curling.
