This is probably the most important thing.

If you choose the wrong kind, they will a) not absorb enough and leak and b) be ruined in a couple of months.

Rule number 1: the fabric needs to be thick. Those lovely flats with prints are not cut out to be used as nappies. Yes, they are pretty, but waaay to thin. You need to look for flats with fabric weight of 140 to 180 g/m2, like cloth nappies “from the olden days” 😀

Dimension of the fabric should be min 70×70 cm, because then you can use them in folds when your kid gets bigger as well as inserts for the AI2 system.

I prefer pure cotton. It is a natural material, can be washed on high temperatures, durable, it’s gentle on the skin and the skin can breathe. You can also use vinegar to make it soft.

I know that there are bamboo flats, which absorb a lot. But, they need to be washed at max 40 °C and there is no way that I’m washing poop at lower temperatures. Tried them for putting under my baby, they got deformed even at recommended washing temperatures.

Bear in mind that I live in Croatia, Europe and as I understand we have different washing machines in Europe. Here the recommended temperature for diaper washing is 60°C, so I use the eco cycle on that temperature.

My favorite kind of flats are these organic cotton muslins by XKKO. I also love LOLA flats, but those cannot be bought outside of ex-YU countries I think.