How to draw smooth lines with a mouse

Mouse lines come out smooth once you switch on the stroke stabiliser in Paint by Zaweba. It has five modes: None, Basic (a pulled string), Weighted, Stabiliser and Pixel art. Each tool keeps its own setting, so your brush can be heavily smoothed while the eraser stays quick and direct.

A mouse is a poor drawing instrument. Your wrist moves in small jerks, the sensor picks up every one, and a stroke that felt like a curve comes out as a wobbly line. The stabiliser sits between your hand and the canvas and evens those jerks out before any paint goes down.

Choosing a mode

Basic works like a piece of string tied to the brush. You pull the end of the string with the mouse and the brush follows behind, only moving when the string goes taut. Small shakes never get far enough to pull it, so they simply disappear. Paint draws a lag line on the canvas between your pointer and the brush, and a dead zone circle around it, so you can see exactly how much slack there is.

Weighted gives the brush a feeling of mass. It catches up with the pointer smoothly instead of snapping to it, which suits long, flowing curves such as hair or the outline of a figure.

Stabiliser is the strongest. It averages your recent movement and has a delay distance, so the line trails behind and smooths heavily. It also has a finish line option, which carries the stroke on to where your pointer actually stopped when you let go, so the end of the line isn't left short.

Pixel art is the odd one out. It doesn't make curves softer; it keeps the stroke to whole pixels and avoids doubled corners, the little L shaped clumps that make hand drawn pixel lines look messy. Use it with a hard one pixel brush.

Setting it up for different tools

Because the setting is per tool, it pays to think about what each one is for. Inking and line work want a strong stabiliser. Shading with a big soft brush usually wants none at all, because the delay would get in the way. The eraser is often best left on None or Basic, so you can make quick corrections without waiting for the brush to catch up.

Start with a moderate amount and draw a few test circles. If the circle comes out with corners or bumps, increase it. If the brush feels like it is dragging through treacle and you overshoot where you meant to stop, reduce it.

Getting straight lines and clean shapes

For a truly straight line you don't need the stabiliser at all. Painting Guides place a ruler, ellipse or perspective grid on the canvas and your strokes snap to it, holding Shift to break free. Mix the two: use a guide for the edges of a building and the stabiliser for the hand drawn curves around it.

If what you need is a clean geometric shape that stays editable, the Shape tools and Pen tools draw vector outlines that never wobble at all, and you can change the stroke colour and weight afterwards.

A few habits that help

Draw from the elbow rather than the wrist when you can, with long confident movements. The stabiliser removes small shakes, but a hesitant stroke is still hesitant. Zoom out for big curves and in for detail, because the same hand movement covers less of the picture when you are zoomed in, which makes it steadier.

Keep line work on its own layer above the colour. If one stroke goes wrong, undo it or erase it without touching anything else. Paint by Zaweba is a free, offline editor, so you can practise as much as you like with nothing to sign up for.