Fig. 19
![Fig. 19](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40494-021-00599-w/MediaObjects/40494_2021_599_Fig19_HTML.jpg)
Micrograph (×5 and ×20 objective lenses) of a M2-G mock-up before (BC) and after (AC) cleaning with Nanorestore Gel® MWR indicate good soiling removal (rating 5) and slight loss of fragments of the ground (rating 4) (arrows)
Micrograph (×5 and ×20 objective lenses) of a M2-G mock-up before (BC) and after (AC) cleaning with Nanorestore Gel® MWR indicate good soiling removal (rating 5) and slight loss of fragments of the ground (rating 4) (arrows)