I was playing with my waterbased markers and a clear stamp, to see if it works and it did.
My clearstamp is from Craft Sensations and from 2016, so you won't find it in the shops now, in fact I was lucky to find in the shops in 2016 ;-)... Any you have, even rubber will work.
All you need is waterbased markers, I used my generic brand ones, but any you have, even your kids' markers that are water soluble will work, I'm sure, like Distress markers or Tom Bow markers but I don't have those.
I colored the leaves and flowers with two tints of markers, then lightly spritzed them with water and stamped on Water art paper from Kippers Hobby, this is a Dutch whole sale supplier for art supplies and I got these precut panels to test things out. I loved how they turned out and not using a lot of water has resulted in no warping.
I have experimented with more or less water, stamping once or twice, it's all good fun. Only thing I didn't realize is as I spray the whole stamp the parts I heat setted get reactivated anyway as my stamp is wet ;-)
I was making sure no bits were touching, but that was superfluous in the end lol.
The sentiments were stamped with Versafine onyx black ink (one is birthday balloons from Simon Says Stamp and the other in Dutch is from Craft-Emotions)
They are the same ones I used on my viking video/card, nail art flat backed diamonds of all sorts.