Now that warmer weather is here it is often possible in many places to operate canister stoves on straight N-butane fuel, which of course does not contain the propane and isobutane that are the main components of most commercial canister fuels from Primus, Snow Peak, MSR, etc. As long as the ambient temperatures remain above about 50°F, canister stoves will work fine with N-butane only, so the much cheaper N-butane fuels designed for table-top burners will work fine.
The trick is getting the N-butane into a regular canister, or, alternatively, using N-butane straight from its original can.
Now available thru Amazon are a couple of adapters that make possible both of these options.
The first one is an adapter that accommodates the use of an N-butane can with a remote canister stove. For obvious reasons (the height!) it is not practical for topper types of stoves.

The next one is an adapter which, when combined with the one above, will permit N-butane fuel to be transferred from the N-butane container into a standard 110g or 230g canister.
The beauty of these adapters is that they allow the use of much cheaper N-butane canisters that typically cost about $1.50 for a 227g can. Probably not a big deal for the solo hiker using maybe 10-15g of fuel per day, but for groups of 3-4 or more on a longer trip in warmer weather this could make sense.
The N-butane canisters are commonly found at restaurant supply stores and very frequently at Asian markets (especially Korean) because the table-top burners are very popular for cooking beef for bulgogi, kalbi, etc.

