The Airbrush software package, supplied on disc, gives budding computer artists a means of simulating the airbrush painting technique. Whereas computer images generally have clearcut lines and sharp boundaries between colours, this program allows soft-edge effects and less clinically sharp pictures, within the limits of the screen resolution and colours available. It works in Modes 0, 1 or 2.

The higher the resolution, the better the airbrushing effect, but as ever, higher resolution has to be traded off against the number of colours which can be displayed simultaneously. In Mode 2, all the non-flashing colours can be used, but the pictures are best viewed at some distance if the coarser pixel size is not to become distracting.

General instructions for use are included as a separate file on the disc, which also contains a number of sample pictures in Modes 0 and 2. Control of the 'airbrush' is from the keyboard, using the cursor keys to move a cross-shaped cursor and the Tab key to apply the spray. The size of the cursor indicates the area covered by the spray and can be varied by means of the < and > keys. The SHIFT key is used in combination with any of the others to increase the auto-repeat speed as required.

A single press of the Tab key delivers a measured amount of spray to the area indicated by the cursor. Thus the density of spray can be controlled by the length of time that the Tab key is held down. Over-spraying and other errors can be corrected by re-spraying in the background colour.

To a limited extent, intermediate colours can be generated by mixing sprays of two different colours - e.g. you can create orange by spraying the same area in red and then yellow. There is provision for saving and loading pictures on disc.

The program is capable of creating some impressive pictures, such as the examples on the disc - a picture of one is shown here. However, whereas computer drawing programs generally offer some assistance, this is essentially a free hand drawing program and relies upon the eye of the artist to get all the shapes and proportions right. I found it useful to load a line drawing generated by a separate program, and use it as a guide to positioning the airbrush cursor. Some patience is also required as the procedure of repeatedly applying a measure of spray and then moving the cursor and/or adjusting its size is necessarily very time-consuming.