Optimal album artwork size

Q: I have a question about the “Other” category on the Summary screen in iTunes. All I’m putting on my iPod is music yet the “Other” section keeps getting larger. I’m sure I had 29 MB before I started and now I have 54.4 MB with 1.16 GB of music. What the heck is filling up the “Other” folder? Also, do you have any suggestions as to the best size of artwork for my music library? I’ve been using 500×500 from Amazon but can I use a smaller size?

– Anonymous

A: The “Other” category represents anything on the iPod that iTunes does not specifically recognize as audio, video, or photo content. This also includes the iPod database itself, which of course grows to contain your track information as you add more content onto your iPod. The other common item included in the “Other” category is your album artwork.

iTunes creates a separate database on the iPod to store your album artwork in order to speed up access when viewing your tracks. Artwork images from iTunes and within your MP3/AAC files themselves are converted by iTunes and stored in this separate database. Since iTunes does not recognize these files as audio, video, or photos, they’re simply listed in the “Other” category.

Artwork is stored on a per-track basis, since you could technically have a different image for each track. Since these images are resized by iTunes for the iPod screen, the amount of storage taken up will depend on the model of iPod you are using, but ranges from about 23 kb per track on the first and second-generation iPod nano to just under 400 kb per track on the iPhone or iPod touch. You can find more detail on this in a thread in our iLounge Discussion Forums titled Photo Storage on the iPod – The Gory Details.

This leads into your next question on artwork size. The short answer is that the optimal size for your artwork is going to depend on where and how you want to view it. As already mentioned earlier, iTunes resizes your artwork to fixed resolutions for each specific model of iPod regardless of the original artwork size. However, despite this, the artwork that is embedded in your MP3 or AAC files will be at whatever size you originally stored it. Therefore, using higher-resolution artwork if you’re only concerned about viewing it on the iPod will simply be wasting space, as the artwork image takes up space in each media file, but doesn’t actually get used by the iPod.

Consider that the highest-resolution iPod display is presently found on the iPod touch and iPhone, and even this is only 320 x 480, which means that the square artwork image display is only 320 x 320.