Yesterday, at my Dragon Ladies Fiber Group, Lisa brought her Christmas present for us to play with. These Derwent Inktense "pencils" are amazing. Permanent watercolor-type pencils blend beautifully on cloth or paper but when dry, they are permanent. The colors were remarkably strong, even when water was added.
I tried my hand with these pencils by drawing a simple bird sketch and found them to be very easy to control, blend, and define my drawing. I think they have many excellent qualities regardless of the medium used. I plan to heat set my sketch on muslin to truly test for permanence.