Custom cursors should not be necessary. For brush or pencil, a dot in a circle works the best; it is a precise, simple and clean solution. In a paint bucket cursor the user needs to realise that the tip of the paint is the actual cursor (something I learnt with trial and error). The dot in a circle can be scaled to have multiple dimensions such as good feedback in terms of current stroke width, brush pressure (higher pressure means darker and thicker strokes). If a custom cursor can provide advantages over these only then it will be worth testing with primary users.

Custom cursors should not be necessary. For brush or pencil, a dot in a circle works the best; it is a precise, simple and clean solution. In a paint bucket cursor the user needs to realise that the tip of the paint is the actual cursor (something I learnt with trial and error). The dot in a circle can be scaled to have multiple dimensions such as good feedback in terms of current stroke width, brush pressure (higher pressure means darker and thicker strokes) and currently selected color. If a custom cursor can provide advantages over these only then it will be worth testing with primary users.