It can be difficult to source well made clothes that fit over real nappies, as most clothes are cut for disposables. As a general rule, you will need clothes that are at least one size larger if they do up under the crotch, or go round baby's bottom. Also, you will find that trousers may well drag your nappy wrap down, because of insufficient crotch depth. This is more of an issue with a newborn baby than an older child, as the ratio of baby to nappy is quite small!
Where it is not practical or desirable simply to go for a larger size to avoid these problems, you could buy clothes cut for real nappies. If you are traveling to the United States or Canada, you will find many more clothes cut for real nappies, including names such as Osh Kosh, and prices will be very competitive. In the UK, we would recommend Frugi.
In the last couple of years easy up jeans have started to appear on the High Street. These are jeans with an elasticated waist band similar to jogging bottoms. This makes getting jeans on over cloth nappies far easier and much quicker for potty training children to take down too. Easy up jeans started in Gap but i've now seen them in Mothercare, Tescos, Primark and lots of them in the Next catalogue this year (summer 2010). They used to be just up to age 2 but now seem to be available up to around age 10.
Another recommendation from one of our customers was the LOGG clothing range in Hennes. They tend to be wider and fit over cloth nappies easily. They are also very inexpensive. You may also like to consider getting a pack of vest extenders, available from The Nappy Lady. These are a handy little rectangle of cotton which snaps onto a bodyvest to lengthen the crotch.
You will find that the more expensive the clothes, the worse the fit over cloth nappies. Personally, I recommend buying vests and bodysuits from Tesco’s, as these are very roomy even in the right age range. Some nappies are of course bulkier than others. On a newborn the bimble, teenyfit or folded muslins make the slimmest nappies. The Bambinex Bamboo nappy is much slimmer and fits under fitted trousers more easily. The Bamboozle Stretch, Easyfit, Bumgenius or Charlie Banana or Fuzzibunz Elite are other nappies that are slimmer overall.