Except that... to make a batch of inversed decals is very costly for me. One person might buy it, maybe two or three, but that's it. And they aren't cheap. So I'd be sitting on inventory I shelled out a decent sum for. I'm not a business so I can't afford lots of inventory or overhead.
I don't recommend using water. In fact, make sure the glass is cleaned first (409 glass cleaner, windex, etc), and dry.
Basic instructions for ALL decals are as follows:
1. Clean the surface you are going apply the decal do. Use 409 Glass Cleaner, or Windex, or similar glass cleaner. Take a piece of masking tape and see if it sticks. If you can move the tape around, your surface isn't clean enough, and you need to go over it again. Those of you who use Rain-X will probably need to clean a lot more thoroughly.
2. Spread out the decal where you want it. In the case of banner decals, fold the decal in half and crease the top corner. That way you have a middle to line up with. Place decal where you want it, and use pieces of masking tape to hold it.
3. On one end, tape the entire end to the glass.
4. After you get it where you want it, peel off the smaller pieces of tape, and pull the decal back away from the window... leaving it only attached at the one end with tape.
5. Peel off the underside backing, starting from the taped end first.
6. Apply the decal using a flat tool to press it down. Once down, smooth it out with your hand or a tool as best as you can.
7. Peel off the wax over backing by pulling it towards the taped end. If you don't pull it in the direction of the taped end, some of the decal might not stay on the window.
And that's it.