Drownerfood: So I gave up selling things and being able to run a few levels ago, now I'm over 400 on weight and my inventory is a nightmare! I'd really like to be able to sort my items by weight, value, name and level, but since that isn't available how do you manage inventory? I'm not really sure what weighs so much, I've sold all the weapons. Any tips on how to figure out what's important?
prottenstein: Apart weapons , you have to sell armors, bolts, horse equipment and hides. These are the heaviest things. Then check the junk
From my experience finishing the game I have to agree with your assessment here. Armor, swords, exploding crossbow bolts, horse gear, trophies and various hides in particular bear hides are the heaviest individually. Some other things aren't heavy individually but you get a lot of them and they add up to being heavy too.
For the most part food and ingredients for alchemy are very light, many/most such items weighting 0.01 which means you can have 100 of them and it only uses 1 unit of weight. But... there are well over 100 if not close to 200 different ingredients and while they're all individually only a small fraction of Geralt's encumbrance, they do add up. So it is a good idea to purge excess ingredients/items from time to time. There are some things that are harder to find or which are used a lot such as alcohest that I'd keep 25-50 of when purging, and I also found arenia and barbicane fruit to be hard to find at times as well as monster feathers and a few other ingredients so I tended to keep many more of those when purging - but most ingredients I ended up only keeping 5-10 max of each purging session.
By far the biggest impact on weight is the first tab and last tab of inventory though with the items listed above, so it is a good idea to offload them sooner rather than later.
Also, at a certain point in the game you end up with more money than you could ever possibly spend to good use. Once you have 40000 or more cash, you can just start purging by dropping crap on the ground everywhere that you would normally sell for cash. Just don't drop anything you may regret leaving behind - only drop shit you definitely 100% don't care about, which is most crap. If there is the slightest chance you might need or want something again then sell it at a vendor you favour such as the ones at Crow's Perch or Novigrad, which were my preferred vendors in game. If you change your mind all vendors seem to hold on to the reams of crap you sell them and nobody else ever buys the crap from them. I'm surprised they don't go bankrupt from poor cashflow management but then this is a fantasy game and not an economic simulator too so... :)
If I could make one single genie-wish change to the inventory, I would have the game sort all of the books to the BOTTOM so that it goes oils + bombs + potions + decoctions + books instead of the current item sort order. Having to scroll 10 pages over books and crap to find potions is annoying if you hold on to all the books/notes in case you need them or for some other reason. :)