Not sure if this is even what you are talking about so check
it out and see.
http://www.paper-paper.com/cling.html

Another way to make windowclings, without using your computer, is to buy clear vinyl at a fabric store. (It comes in various weights, and is about 54 inches wide.) You can color on it with markers. I haven't tried using the glass paints, but I'm betting they would work on the vinyl.

To make it cling to your windows, just wipe over the window surface with a damp sponge, then apply the smooth (undecorated) side of the vinyl to the damp window. It will cling (for as long as you want it to... and then it will peel right off).

Note that you can NOT run this vinyl through an inkjet printer with results. The window cling material made for computer printers is a special type of plastic.

One type of inkjet window-cling material I have used is "Color Inkjet Window Decals" by Xerox. Don't know if they make this product any longer. I'm sure other brands are available.

I use the Gallery Glass paints to make my window clings. If you dont want everything outlined with the liquid lead then you can apply one color, let dry, cut to shape and apply the next color. Its easy to work with and alot of fun!! I have made things for door windows and one of those florecsent kitchen lites. Try it, you'll get hooked. And they peel off windows mirrors, etc and you can reapply elsewhere.

If you can find it, Hammermill makes clear window decals that can go right through your inkjet printer. I bought mine at Walmart about a year ago and haven't had any luck finding any more.

what GREAT ideas!!! thanks to all

Check link below for several brands that are still making window decal material that goes through your PC printer...

Or just go to a large office supply store and look. Perhaps at WalMart, too, but not certain.

Lots of variation in prices. You can also find it on eBay. Just search by name brand or relevant search terms.

Here is a link that might be useful: window decals for printers on Froogle

I bought my window decals at Office Depot. You can get window clings that can be printed with your printer. This link has several sites that sell the clings. There is a big difference in pricing. I have not used these yet so I can't recommend any brand or site.
http://www.google.com/search?hl=en&q=inkjet+window+cling&btnG=Google+Search

Just ran across this post that I'd saved years ago! Have not tried these methods, but thought I'd copy it here for those who want to try a different approach...
Make 'window clings' and 'appliques' with Heat-N-Bond!

Posted by Scooter (Scooter@nospam.com) on Wed, Feb 7, 01 at 15:58

I've discovered that you can make great looking window clings and appliques by using magazine pics, inkjet prints, fabric, etc!Using a magazine pic as an example, just cut a piece of the medium weight vinyl about an inch larger all around than the picture you have chosen. Iron the vinyl between 2 pieces of plain computer paper (the vinyl will shrink a bit when ironed). Continue ironing the vinyl for short eriods until you see no further shrinkage. Then iron a piece of Heat-n-Bond (cut to the same size as the shrunken vinyl) to the front side of the magazine picture. Remove the paper backing from the Heat-N-Bond and place the piece of vinyl on the Heat-N-Bond covered picture. Place the paper backing from the Heat-N-Bond over the vinyl and bond the vinyl to the magazine picture. Once everything has cooled, place it in a shallow dish (or the sink) and let it soak in plain water for 2 or 3 minutes. Then rub the back side of the magazine picture with your finger and all of the excess paper will roll right off! You have now made a really cute window cling! You can use it as-is, or you can prepare another piece of vinyl as stated above and iron it to the side that you just rolled the paper from. For an applique, just iron a piece of pre-shrunk white fabric to the side that you rolled the paper from! If adding the additional piece of vinyl or fabric back, DO NOT use additional Heat-N-Bond... There will be plenty already there, since none of the 'adhesive' actually 'soaks' into the vinyl.

You can also use inkjet prints... just lightly spray on two or three coats of clear enamel, letting each coat dry, before beginning. Fabric can also be used, giving fabric appliques a whole new look.

Any white areas of a pic will be almost clear once the paper is rubbed off... that is the reason for the white fabric back if you don't want the 'clear' look.

You can even combine several pics, add text, etc. all in the same project.

I'm going to try making some write on/wipe off boards using this technique from all of the printable worksheets available on the net. It should also be really good for making 'paper dolls' with clothes that 'cling' as well!

Also, for window clings, just make sure you are sticking the vinyl side to the window and that the window is clean. If the window is clean and you still have trouble, just wipe the window with a damp cloth.

The vinyl comes in four different weights, and the Heat-n-Bond comes in Lite and Heavy. Play around with all of them! I wouldn't use Wonder Under, because it is a 'web' and needs higher heat and Heat-N-Bond is a solid sheet and requires less heat.

Hi, I know this is coming a tad late, but I was searching for the same thing and found the paint that works for it.
It's called marabu window cling paint..you can find it online.