This is a maskless technique (similar to projection lithography) to create patterns in a photosensitive resin (photoresist).

Bozhi Tian has developed an environmentally sustainable method of microfabrication that uses water and natural materials—including paper—to create and transfer patterns. The process draws ...

Such patterns can now be artificially reproduced ... On the other hand, substrates patterned using the latest microfabrication techniques, such as electron-beam lithography, are expensive.