Hi Jill, I’ve used a backpack for some of my domestic trips where it’s more by car or just one flight, but this 30-day trip in Europe that just ended is the first time I used one for an international trip.
First, I looked for a backpack that I liked the style features and fit me properly. I also needed to see how much weight I could comfortably carry. I ended up with the Cotopaxi 35L, and dropped the total weight of the backpack packed down to less than 13 pounds through a lot of kitchen scale measuring decisions between items, etc. Ideally I was hoping for 11-12 pounds, but settled on my amount.
I practiced with my backpack filled by taking mile walks around my neighborhood and also going up & down the set of stairs in our house. I also practiced putting it on & off my back safely, so I wouldn’t torque my back during the trip.
It was very comfortable for me during the trip - so much that I just walked the two miles from the hotel in Split instead of a taxi to the marina to catch a ferry. And it certainly was SO much nicer going up & down all of the stairs during the month. For reference, I’m retired, in my mid-60’s and not slender.