Patch 1.3 adds the ability to store items that players may wish to save for later use, without forcing Geralt to carry them everywhere he goes. The storage interface is accessible by selecting a new dialogue option ("Chcę skorzystać ze schowka.") while speaking with certain characters, or by interacting directly with a nearby storage chest using when "Przechowaj lub odbierz" is displayed. Items left in storage are automatically transported between akty. Although storage is free, there is a possible bug which prevents items from being collected from storage if Geralt has no money.
Dyson Bóbr and the chest in the southwest area of the lower level of karczma w Flotsam, near the door to the burdel. There is a known bug if you access storage in chapter I where your items can disappear if storage was initially accessed through Dyson and not the chest directly.
Rajmund Gessler and the chest at the north side of the Obóz ciur on Roche's path. Alternatively, Geralt can talk to the innkeeper and use the storage chest in his room z Karczma Kocioł, if he follows Iorweth to Vergen.
Beware: On either path, Geralt will cross the mist / battlefield to get to the other location as part of a quest. If he is on Iorveth's path, he has access to the camp followers' encampment and Raymond's chest there. However, that chest will not contain any previously stored items, and any items added to it will not appear in the chest at the Cauldron. On Roche's path, entering Vergen is more difficult, but if Geralt does manage to get into the Cauldron, the chest there likely functions the same way.