I am using 4oz & 8oz wide mouth Nalgene bottles. Both are labeled ** POISON **
Keep them in a zip lock bag cause I can't think of any reason not to. Never leaked.
Dont know if it's been said yet as not going to read every post a 6 oz (actually holds 7 fluid ozs) softish plastic bottle w/ tight fitting flat topped harder plastic screw cap(NO leaks) bought from a hair supply place having 1/2 oz and 30 ml measurements already graduated printed firmly on the sides for thru-hikes which offer 14 total boils using 1/2 oz HEET per 1 1/2 cup boil in a Zelph Venom. The bottle nests perfectly in the Venom inside a Fosters can or Snow Peak Ti Mini Solo with room for a foldable Toaks TI spork, mini Bic (or Mg flint), micro Sea to Summit ditty cloth (used for various tasks), graduated plastic plungered syringe (given free at a pharmacy, they give them out there for dispensing liquid medicine, still looking for the smaller ones I've seen aND used to have several of that are not plungered but are squeezable plastic bulb type), and 22 ft of ZPacks line for bear bagging. I often jam a clean pr of Smartwool PhD's in there too.
For shorter hikes I have 4 oz and 2 oz upright slender plastic bottles. If you order a nice Zelph made alchy stove a nesting UL 4.5 oz bottle w/ tight fitting screw top foldING nipple dispensing cap and Nyquil type measuring cups are thrown in.
I carry the least amount of fuel required for the trip or between known resupplying. I might even carry a few ozs less than anticipated expecting to heat/boil water a few times in a very small very contained warming/heating campfire. To me one of the advantages of alchy stoves is the ability to really gram weenie fuel (a consumable) usage especially desirable on shorter SUL trips.
You should best know your specific fuel needs based on your stove, cooking, abilities, etc.
1) HEET bottles tend to leak around the opened caps
2) Might be on a short trip where only 1 or 2 oz of HEET arerequired so why should one carry a larger or heavier bottle than needed? To me this counters one of the reasons to use an alchy stove which is to minimize carrying uneeded fuel wt, container wt, or volume of such container. Think about it. Cant carry just 2 to 4 nights isobutane (compressed gas) always so readily. Also, think about the wt and volume of a can even if you do have a partial can of iso. I know it's not a prime concern for everyone but it is for those gram weenieing.
3) For those who want to have all their cooking stuff together in the most compacted space the shape of HEET bottles may interfere with that goal.