What is Plique à Jour and the Plique a Jour Technique
Miniature stain glass window effect in jewelry. Frames of metal holding enamel, with no backing, thus allowing the light to come through. Developed in France and Italy early in the 14th century. There are several methods to create plique à jour.
This jewel of plique a jour is a method of pierced metal. Most artists will use this method with the aid of Klyre Fire, a glue substance, to help hold in the powdered enamels in place before firing. This jewel was created in 18k gold sheet of 22 ga. The use of gold gives you more strength and allows you to create jewels in a thinner gauge.
The Bird of Paradise Pendant is more involved. I have chased the Bird of Paradise in 18k gold sheet of 16 ga. and cut away the negative space. I used 18k flat wire to make the leaves and soldered them in place with hard solder. With such large open spaces the use of foils aid in holding the enamel in place, until fired, then the foil is removed. In this jewel the stone setting took place before the enameling. Less worry of cracking your enameled piece after firing.
This is a pair of cloisonné earrings with a drop of plique à jour leaves and a ruby. I would never get a stone cut like this much less be able to afford it. The leaves above the ruby are made in 18k gold, 18 ga sheet pierced and sawn out, then filled with enamels. Again foil is used to support the enamel while firing.
The enamels in this case were laid in after the ruby was set.
This enamel jewel of plique a jour is made of 18k gold sheet. The pedals have been sawn out and formed in a dapping block. The opens were pierced and filled with enamels using foil for support. And assembled after firing all the enamels. The stones are fabricated on screw post and allows it to be assembled in such away the pedals all turn.
A few helpful points I have come across in my research,
Millenet in Enamelling on Metal states to use larger granules of enamels, consistent in size for plique to acquire a clearer transparent. Also he puts the Klyre Fire against the cell wall then adds the enamel.
Another point is to use soft firing enamels= higher expansion rate enamels, which mean these enamels melt sooner than others allowing it to fuse faster and not fall through the openings.
If necessary to use Klyre-fire to hold the enamels in the opening while firing, use one part klyre-fire in 5 parts water in your enamels. After washing your enamels pour off all the water then add the Klyre-fire mixture to the enamels. Too much Klyre-Fire will cloud your enamels, so pay attention as the day goes, the water evaporates and makes the mixture stronger of Klyre-Fire, so add a bit of water though out the day.
The use of a consistent gain size gives the best clarity but also using a smaller grain size can be used such as 150 mesh, as it is lighter and easier to fill the openings without falling through. It is a bit tricky, but you are making a water bubble with your brush in the opening. I place my brush parallel to the surface of the metal and opening, and just touch the edge with the brush and move it across the opening, this usually makes a water bubble. There is enamel on your brush at this time, and a good bit of water.
Fire the enamels just to orange peel until you have the cells filled with your enamels, then carefully fire to maturity. This way the enamels are less likely to fall through.
And check out The Ada Brooch, an amazing piece of Plique a Jour
https://alohilanidesigns.com/the-ada-brooch/