Wicking

From CntWiki

In cloth nappy terms, wicking is the process whereby wetness seeps from the nappy onto other clothes the baby is wearing.

This may happen because the nappy is not absorbent enough for the baby or because the baby has been left for too long between nappy changes.

Some nappy fabrics, in particular microfibre, are associated with wicking. This is because of the way in which the material holds liquid (between rather than within fibres). It means microfibre can act as a sponge - squishing out liquid, causing leaks, when the baby sits or lays on the nappy. This is known as compression wicking.