how to customize a bouffant cap

We all know that the most common sizes of a bouffant cap are 19'', 21'', 24''. While there are also some customers needs specific size like 54-56.5cm when the elastic band is moved, to better fit their clients. How to meet our customer's demand? Now we have a good solution. Firstly, we cut a circle fabric at diameter 23''(around 58.5cm). Then, when workers make the cap with machine, they will cut at least 2cm fabric. It sounds simple, while each worker has different skill, we have to train them to pay special attention to the size and keep more than 99% caps are between 54-56.5cm.