How to cover up pencil and charcoal marks

Reader Question: I used a combination of charcoal and pencil marks on a hard canvas board that I had coated with a couple coats of gesso. I want to use acrylic in kind of a watercolor way (like Charles Harrington).

I find that I did some wrong measurement with my grid lines and some wrong lines in my redoing of the drawing in the grid. Even though I used charcoal and light mechanical pencil, it does not come completely off. I am afraid that it will show through when I do my painting. Any suggestions?

If you are planning to use the acrylics in a thinned, watery way, then there is indeed a good chance that those misplaced charcoal and pencil lines will show through the paint.

The best thing I can suggest is to carefully paint over those charcoal and pencil mistakes with white gesso. You might have to use a small brush so that you don't accidentally gesso over the lines that you want to save.

If you have to, you can do 2-3 coats of gesso over the mistakes until they are covered up. Depending on how thinly you use the acrylics, the tone of the paint might look differently on the areas that were gessoed over, but it's hard to say.

Suggestions from Site Visitors

Next time try not doing your sketching on the canvas. Plan your whole painting, gridlines and all on a sheet of paper the same size as the canvas. When the drawing is complete and perfect transfer the finished product with no mistake lines to your canvas, panel, paper using carbon paper. I get a 36” wide roll of plotter paper from an office supply store which can be cut to most canvas sizes, carbon paper also comes cheap at an office supply store.
— Lyall Brownlee
Sketching your design in watercolour pencil is great - an earthy tone is best - and then it just blends into the paint as you work :-)
— Missy