I have used them on clear stamps and they work great!! I really like them, they are fun!!! I haven't tried using them with dark paper though, sorry I can't help you there.
Is there a "How To" video on StampTV for the Faber Castell Gelatos? Do you find the images are as vibrant as using ink pads? I tried them but found them to stamp a very light image and think I may be doing it incorrectly.
I don't believe Gina has done a video using them but you can check You Tube, I imagine there is some there!! I only have a few of the colors and of those no, my images are subtle and not anything like an ink pad. I'm guessing they are all that way due to using water. It is a fun, different technique!
Hi There! Faber-Castell Design Memory Craft here. When you use clear stamps (like the one we include with Gelatos), we recommend that you prime them with an eraser first. Then you can rub some Gelato on your stamp and lightly mist before stamping. Some people like mist, apply Gelato, mist again for watercolor effects.
While you can use Gelatos to stamp on dark paper, some of the darker colors may not show up as brightly as the metallic or lighter colors. One thing you can do to see the darker colors on dark paper is create a tinted Gesso Gelato to stamp with. To do this, mix the Gelatos with some Gesso to tint the Gesso, and apply that on your stamp. Gesso has a white base and creates an opaque background for the Gelatos color to shine through on. Another technique is to stamp using our new Stamper’s big WHITE pen on dark paper, and when dry, rub dry or wet Gelatos over it to see the Gelato colors.
You can also visit our blog for more techniques and inspiration at http://www.designmemorycraft.typepad.com/.