Square brushes for colouring shading sketching and linework!
The 'Square-ish Brush' is best used at 15px size with 600dpi canvas. It has nice pressure variation and can draw very thin lines.
The 'Square-ish Brush Shadows' is best used on a multiply layer with lighter colours. With white you can blend colours together.
The 'Square-ish Brush Colour' is for adding areas of colour with textured edges.

Brushes
Update history
Fixed an issue where the brushes didn't paint colour on vector layers.
Old version