A very often used device to separate colours and define shapes is to do this with thin wires, what we call cloissonné. The result is stylised and graphic and the technique has become a favourite by its own merits. Champlevé, often even more stylised, can also help us in this department, and the raised metal sections become a very predominant part of the design.
Another way of dealing with this is to eliminate the sheen of the metal substrate by blocking it with a layer of opaque or semi-opaque (opaline) enamel, and then work with transparent enamels over it. Doing this we alter the look of the enamel significantly, to the extent that it may not even be recognised as enamel by untrained eyes.
I first came across this "technique" via a school exercise, while I was a student in the enamel department of the arts and crafts academy Llotja, in Barcelona.
Apart from the all-important workshop class, we also had other classes, as I realised later, as important as the workshop: such as Art History, Technical drawing, Artistic drawing (with live model), and so on. One of the subjects was Projects, and there we worked with pen and paper, many sorts of paints, and a great array of unorthodox materials. One of the assignments was to work freehand with watercolours, anilines and whichever other paint we came across, on big pieces of paper, and then select fragments of these "paintings" to form a composition in a rectangle.
With this we moved on to the workshop, and the task was then to reproduce this as faithfully as possible in enamel. This wasn't as easy as I expected it to be. It was also great fun.
My composition revealed much of the white paper below, and had bleeds, sfumatos and clean edges of colour characteristic of watercolour. Not often associated with enamel, though. Of course, the only way to go about this was to eliminate the sheen from the metal substrate. But I went with opaline enamel instead of opaque, since it has a softer porcelain appearance, as a bit of the light penetrates the milky layer of enamel on its translucent upper surface, and is then softly refracted in all directions. Opaque enamels completely stop the light, and then the appearance of the transparent enamels on top is more flat and harsh. This may be the desired effect, but I most often reach for the opaline enamel. My favourite for this task being the pure white, porcelain-like Schauer 64.
In class we only used Soyer enamels, though, so I must have used Soyer 101, opal white, for my school exercise:
Soyer 101 is rather sheer, even when fired to the top of its opalescence (short fires will leave it almost transparent), and it takes a few layers to hide the pinkish hue of the copper below. Which may be a good thing if one wants to reproduce pinkish skin tones. Gold substrate, or layers of peach, golden and chocolate enamels will work well for achieving honey-coloured to deep chocolate skin tones. Unless going for some sort of mythological creature, the bluish tinge of silver better be countered with other hues, or eliminated with opaque or transparent enamels.
And so it is that this school exercise proved very useful to me years later, when I wanted to achieve a particular effect, like that of working with watercolours, which in many ways behave just as transparent enamels.
Both watercolours and transparent enamels bounce part of the light back in colours, but also let the rest of the light go through to the substrate, instead of absorbing it (like gouache or opaque enamels), and so the only way to achieve white is by not painting over the substrate (the white paper or the opaque/opal enamel). Multiple or saturated layers of watercolour provide very vibrant, luminous colours, precisely due to their transparency, as the light can in a way illuminate them from within. This is even more so in transparent enamels, where the thickness of this layer is significant. These pieces, just as watercolours, are difficult to photograph, since the very subtle play of light is partially lost.
In this picture, the opaque details of on glaze and their shadows below help to show the depth of the transparent enamel underneath.
I will now illustrate the point with the step by step process I followed to enamel this necklace:
I started with a white base of Schauer 64, just like one of these:
I then wet packed my design with finely ground transparents, so that I could obtain the detail I wanted:
To give more depth to the stamen, to avoid a "step" between the green and the white, and to transition a soft green at the base of the flower, I applied a layer of fine Soyer 101 to the flower:
I then proceeded to enamel the stamen with yellow again and added some emerald green enamel to the bottom for depth, and I was done with the transparent enamel:
Now, further detailing can be obtained with successive layers of transparent enamels. These two pieces were enamelled in this way:
In the case of the calla lily, however, I chose to do most of the detailing with opaque on glaze paint, of which the pieces above have only a few touches, which would amount to fine detailing over a watercolour with gouache or ink. This was my first layer of oil on glaze paint:
And the second and last layer, for shading of the flower and veins on the leaves, fired:
Layered colour palettes are very useful when enamel painting. They show us how different colour look when layered on top of eachother. Palettes with several layers also help us see how an enamel gains saturation with successive layers. Colour palettes with the transparent enamels layered over opaque white and opal white are also obviously very useful for painting over white.
I also like to use one layer of transparent enamel over Schauer 64 for a soft background where I then paint with on glaze paints:
See progress here.