This is done several ways.
Most all images are stamped in black dye or they can be embossed with black ink/ clear EP (or black EP if you prefer) on white card stock (cs or CS) unless specified by the hostess. Images are clearly stamped, no smudging and are not colored.
If you get a bad impression, re stamp, and attach to the sheet over the bad impression with a staple away from the image.
Stamp credits are important in this swap to help those who are shopping for the images they see. Please refer to an Angel Policy list before stamping images (link to article below).
Size of paper to be determined by hostess but here are examples:
1. Full sheet of cs with images filling up the page but room around the image to cut it out or leaving a border around it to frame the image.
2. Half sheet, same stamping routine as the full sheet.
3. Images all stamped on a quarter sheet of cs. (most likely one image per quarter sheet)
4. Images can be stamped on leftover papers or cs any color ink, embossed or not. Typically this swap is run with a mass of images from each person. Credits should be put on the back of each paper/cs. (I have done this with 20 unlike artsy images on scraps appropriate to the image.)
Swaps can be an open theme meaning any images you have and can contribute on your sheet or can reasonably fit on the cs. Themes are flowers, fairies, cats, dogs or what ever you may be interested in.
Amount is to be determined by the hostess also.
Some image swaps are even, some are not.
Some require one for every person. A sign up cut off date is established and swappers are notified as to how many sheets they must do by a certain date. This is really exhausting because if you have a large swap and have some dropouts, extra sheets should be sent back. To prevent this from happening, a 6/6 or a 6/5 swap is reasonable if you have 12 or more people and a few drop out. Also, creating too many sheets is very boring to stamp and can be discouraging to newbies who try a swap like this for the first time and can be expensive to mail.
Swap hostess should also specify if the images are to be used and create something to be scanned and put in albums if it is done within a community or a creation mailed to the image owner.
Image swaps are good so you can get an idea of what stamps are out there by seeing what other people have access to.
The images are a good way to get extra images you don’t (in particular to a favorite theme or subject) have and create RAKs with them.
Mailing tip: use a manila envelope for a return: 9 by 12 for sheets, 6 x 9 for half sheets. Add a thin piece of board to prevent mangling. Label your envelopes: “Do Not Bend”.
See also Image Mingles and Image Challenges.
Also see Angel Policies for Stamp Companies