I decided to play with the Urban Snapshot stamps. Since I have been making quite a few CAS cards recently I have continued this approach with much white space although it is not white! Just a fair bit of background and carefully placed focal images.
I have used a canvas frame which does not have a solid back to stamp onto, so one of the techniques I like to use in this situation is to stamp onto tissue paper. To then tear out the image to reduce any hard cutting lines which are more likely to show when it is glued into place. It is attached to the canvas using Matte Medium. I used Archival Smokey Grey ink to stamp with and dried it with a hot glue gun before introducing Matte Medium to it.
This is a close up of a section that I particularly like. It shows layers of Fresco paint that have been built up plus the use of the paint with rubber stamps and jar tops. You can also see how well the stamped tissue paper has merged with the background. You would never know this technique had been used.