As I've collected mugs, I've created a bit of a classification system in order to determine how much I'm willing to pay, if the mug is worth the bag space, and to categorize my own excitement at getting the mug.

Class I mugs are the most straightforward mugs. Standard mug stock, just a printed on image, text, or other pattern. I mostly don't buy these anymore to save on storage space, but if I'm out of other options and I want to get one for a city/country I'm visiting, then they are on the table.

I'm usually only willing to spend $10 or less on them, but if you're at a tourist shop, they can be more.

Class II mugs are the next step up. They're still mass produced, but they have a unique flavor to them that makes them more interesting. These end up being quite a few of the mugs I find. The uniqueness for these is subtle still, things like a textured graphic, an interesting texture, or a mildly novel handle. I'll easily spend $20 on these.

Class III mugs are where mass produced mugs end. Unique shapes of mass produced mugs, or fairly standard hand-made mugs make this class. These are what I usually try to buy these days, and will easily spend $30.

Class IV mugs are hand-made, generally by the person I bought them from (as far as I know). They have unique shapes or features, and are very much one-of-a-kind. I've spent $60 on these before can could see spending $100.

Class V mugs – well this category is still theoretical. In my mind, it's mugs I or a loved one hand makes. I'm working on a process for 3D-printed dishwashable nylon-core mugs, with a primer, paint, and dishwasher-safe sealant for food safety. I'll certainly make a new post when I have one ready!