Pastels are rather laid back: they blissfully embed themselves in the contours and hollows of the support medium. Applying an acrylic primer before adding colors will allow you to create visual effects. An intense result!
What you need to know
The more textured your paper, the more its tint will show in your work. By using a primer or acrylic gesso to strengthen your base, you commit yourself to composing your piece on the basis of this new parameter.