Decanting/Combining NPCs
There are NPCs who can decant potions either to make 1, 2, or 3 dose into 4-dose potions. Or to convert 4-dose back into 3-dose. There is also an NPC who can combine enchanted jewelry to consolidate the charges.
Decanting Potions
Bob Barter is one of the Market Price Guides located in the northwest corner of the Grand Exchange. With the update of 9 September 2008, players can now talk to him and he will combine any 3-dose, 2-dose and 1-dose potions in your inventory into vials containing 4 doses. He will also combine barbarian potions and calquat kegs.
Un-Decanting Potions
Zahur is a woman in Nardah who will decant 4-dose potions into 3-dose potions, for a small fee of 50 coins per inventory converted (regardless of how many potions are in inventory). The player does not have to supply empty vials for the decanting, as Zahur's fee covers this service. Indeed, Zahur will not use a player's vials if a player brings some.
The player should make sure to have room in inventory for the potions generated this way, or Zahur will refuse to decant them. (20 4-dose potions would become 27 3-dose potions, and one 2 dose potion, filling inventory entirely, and thus is the maximum that can be decanted in one 'go'.)
Combining Enchanted Jewelry
Murky Matt (aka Matthew Grey) is one of the current "Market Price Guides" near the east side of the Grand Exchange Market in north-west Varrock.
After the update on 20 October 2009, Murky Matt can combine players' enchanted jewellery charges, for a more efficient use, much like decanting. Two games necklaces with 1 charge each can be converted into one games necklace with 2 charges, for example.
After the update on 15 December 2009, Murky Matt would combine ferocious ring charges.
