Faber-Castell PITT Graphite Crayons

Wish I knew about this before.
I use this to lay down a layer of graphite on the back of a picture I want to trace. It works wonderfully and allows me to transfer images to watercolour paper. The image is way cleaner and less messy than transfer paper. It also saves me tons of time as I only have to trace the image once versus having to trace the image 3x using tracing paper. All in all a win. Glad I found out about it.

I use these with big sheets of vellum for loose product design sketches

These are wonderful for my portrait drawing class. They blend really well.