I love these crayons and go on about them, well, probably a bit too much, but they're just great! I use them daily for my own work, my workshops and illustration club at school with the kids.

Here's the blurb:

Kitpas crayons write smoothly in bright, solid colours. You can draw pictures or write messages on paper, glass, mirrors, whiteboards and more. Or dissolve them in water for watercolor painting. Kitpas art can be removed from any non-porous surface with ease. Just wipe with a damp cloth.

• Buttery Smooth - Draws smoothly and vividly, even for children* who have not yet developed strong motor skills.
• Erasable - Wipes away quickly on any non-porous surface such as windows, mirrors, and white boards. 
• Water Soluble - With a few strokes using a Kitpas water pen, your drawing will transform into a beautiful watercolour. 
• Made in Japan.

*Kitpas is designed for kids 3 years and above.