IGIS Tech Notes describe workflows and techniques for using geospatial science and technologies in research and extension. They are works in progress, and we welcome feedback and comments below.

The colourful circles or squares printed on the edges of food packaging might look unimportant at first glance, but they serve a crucial role in the packaging industry.

Cyan, magenta and yellow, along with black, make up the CMYK subtractive colour model used in printing, while red, green and blue make up the RGB additive colour model common to electronic screens.

The CMYK bulb by Dennis Parren combines a white main light source with coloured LEDs in red, green and blue to cast shadows in cyan, magenta and yellow.