If you take a lot of screen shots in OS X using the built-in screen capture functionality (e.g., cmd-shift-4) and present them to other people, you should really consider changing one of the default OS X settings. This is especially true if the content contains a lot of text. Consider these two captures of a random gDoc form:

Lossy capture using JPG

Lossless Screen Capture Using PNG

You can see the difference quite clearly. The jpg looks blotchy and the color of red has been distorted. This is because the JPG format will degrade image quality to produce a smaller file. Given that we’re talking 9 vs. 13 KB in this case, the savings don’t really matter. What does matter is that the image looks terrible and makes you look oh-so-non-tech-savvy.

The solution is quite simple if you’re using OS X. Simply change the default format for screen captures. Launch the Terminal app and issue the following commands:

defaults write com.apple.screencapture type png
killall SystemUIServer

That’s it! All of your screen captures will now be in the much cleaner PNG format. If you decide you’d rather have JPG again, just replace “png” with “jpg” in that first command.