Back in April when I was about to launch this version of the site, I was preparing the application icons found on the ‘ about’ page by asking each company to send me PNGs, before the very talented Jasper Hauser informed me of a neat little trick that would allow me to do it myself. Although extremely simple and involving just the Finder and Preview, you can make your own PNGs (and we’re talking the full 24-bit alpha transparency kind) straight from app icons on your hard drive; and as it appears that I wasn’t the only one to be in the dark about this, I thought it was about time to share the technique.

Step 1

Let’s say I want to create a PNG for Twitterific. First, find the app in your Applications folder (or wherever you installed it), highlight the file, and hit cmd-i to bring up the ‘info’ window. In the top-left of that window, you’ll see a small version of the app icon, so click on this and you’ll see it highlighted with a faint border. Hit cmd-c to copy this to the clipboard.

Click on the image above to view the full-size version on Flickr.

Step 2

Next, open up the Preview app and go to File > New From Clipboard; you should see your icon appear in Preview’s main window. From here, you can then save it to the PNG format, or indeed any other format you wish. A word of warning, though: Saving the file in Photoshop (PSD) or TIFF format – even with ‘Alpha’ checked – will convert the alpha channel to pure black, so you’ll want to use PNG as the format if you want to keep all that lovely transparency intact.

Click on the image above to view the full-size version on Flickr.

And that’s it! Simple… but rather handy. Post a comment if you’ve found this useful or if you know of any improvements / similar tips. I’m afraid I don’t have Leopard so I’m not sure if the newest version of Preview behaves in the same way. Please let me know!