Ive started a sketch of my next DMP with white charcoal over tinted gesso. Since the subject is our family dogs, I’d like to secure my sketch to achieve an accurate likeness. Usually I wouldn’t worry about the paint mixing with the charcoal, but here I want the sketch to remain as I paint over it.
My question is can I or should I use a permanent or workable fixative on my sketch? The art store has both types in aerosol spray from Grumbacher. I will be using WN oils with Marks slow dry medium.