Here are my suggestions as to what to take with you when walking the Via Francigena, or any other long-distance walk - I assume the gear required for the Camino de Santiago would be pretty much the same (comments welcome!)
I used a 50-litre backpack, which was generously sized for the stuff I carried and could easily fit a day or two's supply of food and water as well. I did see people walking with smaller packs; larger is not really necessary, unless you're planning on carrying camping gear.
|My backpack in vertical cross section|
In one dry sack contains a thermal sheet sack, pyjamas, a lightweight quilted jacket which doubles as a pillow when rolled up (which I have never actually had to use in either capacity, as a jacket or a pillow) and a microfibre travel towel. Yeah, I hate microfibre too, but you really can't carry around a big piece of wet terry cloth everywhere you go! Microfibre is lightweight and dries instantly. I learned that a small one is sufficient, as all you really do is pat bits of yourself dry with it (it doesn't quite feel satisfactory for rubbing the skin, and is not particularly comforting to wrap around you either; find another way to preserve your modesty, such as getting dressed!)
In the other eight-litre dry sack I carry my complete wardrobe: three pairs of socks and underwear, one T-shirt, one spare pair of zip-off pants (not really necessary, actually) and my luxury outfit: a little black dress, a pair of leggings, a bright blue cotton cardigan and a matching silk purse. I called this my Evening Dress because I put it on every evening after getting to my destination and taking a shower.
Every morning I put on my clean T-shirt and underwear and the usual zip-off pants, and then - unless the night was particularly dry and windy - decorated the outside of my backpack with the previous day's washed but still damp socks, underpants and T-shirt, which would then finish drying out during the day. (One way to tell pilgrims from regular backpackers is by the socks pegged onto their backpacks!)
At the top of my pack was my rainjacket and my toiletries bag; at the bottom, a plastic bag containing a pair of sandals and a pair of rubber flip-flops for showering. A single pair of waterproof (non-leather) sandals such as Tevas would have been better, fulfilling both functions.
|My backpack in vertical cross section|
My last item was a ziplock bag containing miscellaneous essentials such as a small bottle of liquid detergent for washing clothes, a piece of twine and half a dozen plastic clothespegs for improvising a laundry line where none was provided, a small squeeze pouch of sunscreen, an emergency sewing kit and a snakebite kit (neither of which I had to use, I am happy to report). I also carried a Spork and a plastic food box - handy for preventing baked goods or fruit from getting squashed, for packaging up leftovers on the occasions when I had cooking facilities, or for collecting blackberries along the way! I carried another plastic container full of nuts and dried fruit (trail mix) for emergencies and pick-me-ups along the trail, and two 750 ml bottles of water. Though once the hottest weather was over, and I had realised that water fountains are quite frequent along the Via Francigena, I often filled only one of them in the morning.
My backpack also has a small waist pocket for things I like to keep handy - pepper spray (another item I am happy to say I never used), a swiss army knife (used only for stabbing apples and pecorino cheese), a power bank for recharging my phone when batteries get low, as they do when using GPS tracking; a small flashlight and a flourescent wristband to wear when sharing the road with cars. In a separate waist pack I keep my phone (in a waterproof case if there is any chance of rain), wallet - no keys, except perhaps a hostel key in the evenings - maps, guidebook and credenziale: an item which deserves a whole separate post of its own!