0:08 Glazing is a really good way of bringing together light and dark and creating luminosity. There are lots of recipes for glazing, but it's actually very difficult to get the right formulations so that you have the durability that you need in creating your glaze.
0:26 I'm using glazing and blending medium here and I'm using Burnt Umber because it's a beautiful, transparent pigment. Burnt Umber comes from Umbria, it's a clay that's been burnt so that it's got a much richer, deeper, darker tone. I'm just mixing it into the Glazing Medium here and you can see that it's got a really lovely strong transparency. How dark you want your glaze to be depends on how much pigment you decide to use and you can build up layers of Glaze.
1:10 Here you have two areas of contrast, the light and the dark and by glazing over both of them you can see that it starts to unify the light and dark contrast, but also brings luminosity into the light areas. Really good examples you can find in Rembrandts work, particularly the one in Kenwood House, which is his penultimate self-portrait.
1:35 You can see where the area has been glazed you've got this really strong sense of luminosity emerging from the darkness. Whereas here you've got a very strong tonal contrast. So the glaze is really unifying those areas of dark and light and bringing them together.