Do you have to wet a canvas before painting?

Do you have to wet a canvas before painting? No, you do not have to wet a canvas before painting in most cases, especially for standard acrylic and oil painting on pre-primed artist canvas, but there are specific techniques and types of painting where wetting or dampening canvas is beneficial. For regular stretched artist canvas that comes pre-primed with gesso, you paint on dry surface, as gesso provides ideal absorbency and wetting would dilute primer and cause uneven adhesion. For raw canvas drop cloth used as art canvas, you should wash it first in hot water to remove sizing and pre-shrink, but then dry and prime with gesso before painting, not paint while wet. However, some watercolor techniques on canvas require wetting canvas first to create soft washes. Some artists wet canvas with water or thin acrylic medium to create watercolor-like effects, improve flow, or help with blending, especially when painting with acrylics on raw canvas for fabric art. For oil painting, you should never wet canvas with water, as oil and water do not mix. For floor cloths, dampening can help remove wrinkles. So generally you do not have to wet canvas before painting, paint on dry gesso-primed canvas for best results, wetting is optional for special effects.