they look awesome, what are they like for walking in? Like a few miles in walking boots?
Thanks! These are made in quite a soft yarn so they feel lovely and light on the feet, yet are 75% wool & 25% nylon and superwash, so will stand up to wearing quite well. The black and turquoise ones are pure wool, but a sturdy wool and tightly spun so should be holding up well too even if they would felt in the washing machine. Most sock yarn is 75% wool 25% nylon and superwash and usually also spun a bit tighter to help it withstand heavy use.
One trick is to knit at a tighter gauge (thinner needles and/or more tension), which means more stitches per inch and a sturdier fabric. It's harder on the hands making them, but they hold up to wear much better. Another upside is that the more closely together the purl bumps are the less you feel them against the sole of your foot. If you've got very sensitive soles, you can knit them with the purls facing out, so called princess soles.
How well they stand up to heavy use depends on the yarn, how they are knitted and the wearer (feet and boots). I wear almost all of my socks in approach shoes or winter boots without trouble and will happily go for long walks (up to 8-10 km) in them. I wouldn't wear them in heavy work boots or for really long hikes, mainly because I'm a bit precious about them.
I'm sure they'd stand up to it though, so it's more if your feet are comfortable enough in them (some of mine fit better than others - there's a learning curve to making socks that fit you just so!). I get really hot feet and some of my non-superwash socks have felted a little under the toes for instance, so I don't use those for long walks. Some people wear theirs out in very specific areas, such as in the toes or under the heel, but the beauty of it is that you can reinforce them where you need it by changing the stitch you use. You can even get extra reinforcing thread to knit into high-wear areas, if you want.
I handwash my wool socks even if they are superwash, but machine wash the cotton ones, but that's mainly so I won't get the superwash/nonsuperwash mixed up. Many will just use superwash and chuck them in the washing machine.
I tend to buy scrumptious indie-dyed yarn at £15-20/100g but also got lots of nice commercial ones at £5-£8/100g, which is obviously more economical. (I normally need 70-75g of 4-ply yarn for my size 6-7 feet.)