isMask Print PDF app.project.item(index).layer(index).propertySpec.isMask Description When true, this property is a mask PropertyGroup. Type Boolean; read-only. Other Tags after application attribute box can Collection color containing current dialog effects enabled error File footage frame from has Items keyframe layer layers name new none null number object on Point position property render seconds set setting settings source text time use user value values with Posted in PropertyBase object and tagged layer, mask, property.