"I could also see these losses in the lead white preparation under the paint.
The New England clam chowder, though tasty and dense with clams, will disappoint diners expecting the traditional creamy white preparation.
The particle sizes of the white preparation layer are small and have a uniform distribution.
The colours are unevenly distributed on the surface, thus revealing large areas of the white preparation below.
The colours were unevenly distributed on the surface, leaving large areas of the white preparation below to shine through.
The XRF spectrum of the walls of the church (points 21 and 23) shows the presence of only zinc and lead, suggesting the possible use of zinc white on top of the lead white preparation.
The main element present is Pb, indicating the presence of a lead white preparation layer, and small amounts of Ca and Fe that may be present in the ground but are also common elements in canvases.
A possible explanation is that MCR-ALS is capable of extracting the secondary fluorescence of the surface Ba and Cd caused by the excitation of the lead white preparation layer.
The wall paintings are made with Tibetan traditional craft and contain multiple ground layers, white preparation layer, paint layer and a thick surface varnish which contained drying oil (maybe tung oil) and pine resin.
Moreover, previous researches, especially in the Moche art wall painting in the Peruvian north coast [6, 7] suggest that the artisans mixed the white preparation to red, yellow and black preparations, in different and controlled proportions in order to get a wider chromatic range.
