Test the nib and surface
Acrylic markers vary in opacity and flow. Prime the tip on scrap material, then test the exact paper you plan to use. A smooth, heavier sheet usually handles paint better than ordinary copy paper, and a protective layer keeps moisture off the table.
Use thin layers
Work around the edges first, then fill toward the center with controlled strokes. Do not keep pumping the nib once the paint is flowing. Let the first coat dry fully before adding a second; thick wet paint can crack, lift, or blur nearby lines.
Keep the line art readable
Opaque paint is excellent for bold regions but can cover a thin outline. Leave a narrow margin around important lines or restore them after the color dries with a compatible black pen. Start with a simple page from the free library while you learn how much paint each nib releases.