I think today I will create a go-to tutorial about preparing sketches and transferring lines. :) In the meantime:
- I scan and make a printed copy of my final sketch.
- I tape the sketch to a piece of transfer paper.
- Once centered on my board and taped down (so it doesn’t move when I work), I trace over all my line work in red pen. This helps me see the lines I’ve already gone over.
- That’s it! Once the lines are traced, I pull off the sketch and transfer and can begin painting.
Regarding your second question, illustration board is thick, cotton fiber, acid free paper that is great for different media, and comes in a variety of thicknesses and finishes. I use Strathmore 500 Series Illustration Board, lightweight with a vellum (textured) surface.
I began using it when I first attended college and haven’t bothered looking for other paper since. It handles all the media I put down without drastically warping.