A high-tech breakthrough could speed up the restoration of centuries-old paintings using a digital mask. Scientists say the method, tested on a 15th-century work, took hours instead of months, and leaves the original untouched.

The method, published in Nature on June 11, uses a digitally printed mask to repair damaged images. Researchers tested it on a 15th-century oil painting that had suffered heavy damage.

Instead of months of cleaning, analysis and touch-ups, this process took just three and a half hours.

It works by digitally reconstructing the missing parts of the painting. That digital image is then printed onto a color-accurate laminate. The printed mask is laid directly over the damaged artwork, restoring the image without altering the original.

This is a multilayer film that is made of very thin polymer membranes that are bound with conservation-grade varnish, and this mask it is a color-accurate printed mask of just the regions that need to be restored in the painting and is otherwise transparent everywhere else, explains Alex Kachkine, a mechanical engineer at the Massachusetts Institute of Technology (MIT), who has led the study.

The process used more than 57,000 unique colors and covered over 66,000 square millimeters. Crucially, the mask is removable, so no permanent changes are made to the painting itself.

The method only works on smooth, varnished surfaces for now. But experts say it could help museums restore more works, especially those lower on the priority list. And it may be a step toward bridging the gap between digital tools and physical restoration.

And Kachkine says it will not replace traditional, human conservators.

A conservator needs a huge amount of background knowledge, skill, and resources to preserve the work and ensure it’s maintained for future generations. This technique changes none of that, he says.

What it gives conservators is more tools, more precision, and more flexibility. It also enables them to work on more pieces than they were previously able to.

This article was provided by The Associated Press.