Legends, Color Bars, and Scales

SOS recommends that users create labels, legends, and text in the form of “PIPs,” (picture in a picture) which are images that can be projected on the sphere. This makes it possible to avoid the warping that would accompany text placed directly on a map, since the closer to the poles the text is, the more it is warped when it is projected onto the sphere.

QGIS allows you to create PIPs using the print composer. This tutorial is a good resource for learning to create most common map accessories. Once you have a legend that you like, you should save it as a separate image. You can accomplish this by unchecking all of your map layers so that none of them are visible in the print composer (note that you have to have them visible when you open the composer, or the legend won’t be created in the first place), and then exporting the image as a PNG. You may want to crop it down in an image editor such as GIMP or a Microsoft Office product like Word or PowerPoint.

For example: if I wanted to create a legend for my earthquake data, I would first open the print composer with one or more earthquake layers visible and create a legend as described in the tutorial that was linked to above. Then I would uncheck all the layers and click Update under the Item Properties tab to ensure that the legend is the only thing visible in the print composer, and click Export as Image.