MyPaint is described by its author as
MyPaint is a fast and easy open-source graphics application for digital painters
The aim of MyPaint is to keep distractions to a minimum. It has an unlimited canvas size, so a drawing can be as big as needed. The most important feature of MyPaint however is the number of brushes it provides, the list is big and therefore the possibilities extensive.
Basic and usual drawings or paintings start by choosing a color – from the color ring for example – and then choosing a brush. Note that many brushes are available by default and can be seen via the different headings on the Brush Selection window. If the selection window is not visible one can bring up the window using the Brush menu and choosing Brush List. Brush sizes can be increased and decreased by repeatedly clicking the D or F keys respectively. The canvas can be set to different forms and backgrounds using the Layers—>Background menu. Layers can also be created and moved above and below each other using Ctrl+PageUp or Ctrl+PageDown or by using the Layers menu. MyPaint can save and load images in PNG, JPG and ORA formats. It is also possible to create one’s own brushes by following this tutorial.
MyPaint is a useful open source software available for Windows and Linux and is at version 0.8.2 as of this post. Painting or drawing skills not included!