Brian or LA Guy could answer this more effectively - and rearviewmirror has just posted a summary - but I'll go ahead anyway. One of the most popular types of Nudie Jeans is the "Dry" denim - it's a thick, raw dark denim with no pre-made fading, whiskering, holes or tears like a lot of jeans nowadays. Looks something like this:
If you wash them, say, once a week, the dye in the denim comes out evenly, and they'd look pretty much the same, just faded. If you go a long
time between washes, the indigo wears off the jeans most severely at all the main points of contact - back of the knees, the seat, and so forth. So when they finally get a wash, they come out looking really rugged:
For people who like denim, this means that they become your
jeans, distressed according to your lifestyle. A lot of this is marketing hype - you can do this with any raw denim jeans, not just Nudies, and you can buy pre-distressed jeans for a lot less - but it'll be fun to see how mine come out. I personally dislike a lot of pre-distressed jeans because the whiskering and fading is inevitably in the wrong places for me - Nudie solves this problem.