My favorite way is to color the block with the Stampin' Write markers in the colors I want to use, starting with the lightest color, working to the darkest color in several areas over the block. Then I spray it a couple of times with water the Stampin' Mist. Some people like to use rubbing alcohol as it dries quicker. Once the color is a little fluid on the block (and not too wet that it drips) you will "stamp" the background where you want it on the cardstock.
Another method to get ink onto the block is to use the Stampin' Classic ink pad or Stampin' Spots to apply ink in areas of the clear block. Always start with the lightest ink and work your way to the darkest. Then you will spritz this with either water or alcohol as mentioned above and "stamp" it on your cardstock.
The last method that I'm aware of is using the Stampin' Classic ink refills. You would add small drops of ink, lightest to darkest, around the block, spritz it, and stamp it. This one can create more "blotches" of ink rather than the fluid watercolor look, but it is an interesting backdrop for stamping.
Once your backgrounds dry, you are ready to stamp images and sentiments over them. This technique allows you to create the color combinations you want for your stamping projects.
In my class we used this water coloring technique and created a set of notecards and envelopes to go inside of a clutch made from Designer Series Paper (DSP). The clutch idea I saw shared by Dawn Griffith from an idea she got from Kris Miller.
We used the Forever Fern stamp set to create the set of cards, the Forever Greenery DSP and Forever Flourishing Dies for the clutch. Check out the video here.
