The section called "Sizes" in here (<a href="https://wiki.ubuntu.com/Lubuntu/Artwork/Incoming/Raring/Box/Guidelines" target="_blank">https://wiki.ubuntu.com/Lubuntu/Artwork/Incoming/Raring/Box/Guidelines</a>) has this: "There are 4 major icon sizes defined that an icon theme should contain: Large, Medium, Small and Extra Small. Each of these sizes needs to be treated separately, simple scaling of a larger icon doesn't work and ends up looking fuzzy and unclear. On top of that, a new optional size, X-Large, has been introduced." But the description below has (in the order shown): Large (48x) Small (22x) Extra Small (16x) X-Large (256x) "Medium" is missing. Also, the sizes I see right now in /usr/share/icons/lubuntu include 16, 22, 24, 32, 48, 64 and 128 px. This is after installing the artwork ppa. I didn't keep note of the sizes before I installed the ppa.