It depends on how absorbent the fabric of the burp cloth is, but most burp cloths should have more than one layer. Multiple layers help absorb more spit-up, keeping both you and baby cleaner and fresher. A burp cloth with more layers can also help keep the integrity of the fabric together after multiple runs through the washing machine. The best material for burp cloths depends on your lifestyle and desires, but generally, cotton, muslin, and bamboo are best because they absorb the most moisture. That’s helpful when you are dealing with a lot of spit-up in the early months.  Fleece, microfiber, and flannel are also options.