A 'true' All in Two nappy is made up of two parts - the waterproof shell and an absorbent insert that usually poppers on to the shell. The advantage of this type of nappy is that you can wipe down and reuse the shell as long as it is not soiled, and just change the insert You can work with 3/4 inserts per shell. This keeps the cost down and also reduces your washing. All in Two inserts are usually hemp, cotton or bamboo or any combination of the above as these materials provide the most absorbency. These inserts often fit the wraps of different brands, so you can mix and match your collection.
There are some AI2 nappies which have shells with fleece linings or sometimes a pocket, and an insert that poppers on. They have the two parts, so are indeed All in Two, but you may also see them referred to as All in Two Hybrids, or Non True All in Two since you can't reuse the shells.
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