Palimpsests are notable for having been reused one or more times over the centuries. Since parchment was expensive and time-consuming to produce, monks would erase certain texts with orange juice or scrap them off and write over them. Though the original texts were once assumed to be lost, the imaging scientists used narrowband multispectral imaging techniques and technologies to reveal features that were difficult to see with the human eye, including ink residues and small grooves in the parchment. Each page took approximately eight minutes to scan completely. These images have subsequently been digitized and are now freely available for research at the UCLA Online Library for scholarly use.