Here are a few pieces with this "Vert de gris" enamel:
ref 70 042ref 20 055ref 20 034
To make this "Vert de gris" glaze, my starting point was my White glaze, to which I added green chromium oxide in various proportions:
Sample 1 and 3 (red dot) hold my interest, I keep these chromium concentrations.
Tin oxide (part of my White glaze) is a rather expensive raw material. According to the literature, it is possible to use zirconium silicate as a substitute. So I replace the tin oxide by zirconium silicate. I use the 2 chromium concentrations selected above and vary the zirconium silicate in two different concentrations:
The top shows the low chromium concentration and the bottom the slightly higher concentration. The lower tests are too close to my " Natural Green" glaze. I therefore abandon the tests with the higher chromium concentration and concentrate on the sample (with the red dot), the one with the highest zirconium silicate content.
I decided to test on larger pieces to see the result:
The enamel is not very covering because of the brush application. I do a thickness test(link to build a tool to measure the thickness of the enamel):
To create this "periwinkle blue" glaze, I started with my white glaze, to which I added cobalt in various proportions:
Previously, I had selected the fourth sample to make my Majorelle blue glaze (link). Today, I decided to use the second sample (red dot) to try to develop a lighter glaze.
The interest of research from the same base of glazes, in this case my Majorelle blue and my periwinkle blue (only the proportions of metal oxides change), is to be able to take advantage of the tests previously made to accelerate the development of a new color!
Here, the test performed for the Majorelle blue with different proportions of tin:
allows me to pass this step, as well as that of a large variation of zirconium silicate.
I therefore decided to directly test two proportions of zirconium silicate that were interesting during the development of Majorelle blue.
I decide to select the sample on the right, the one with the most zirconium silicate which gives me a lighter glaze.
We pass on the test on slightly larger pieces:
The enamel is not very covering, probably due to the brush application.
I then decided to do a thickness test(link to build a small tool to measure the thickness of the enamel) :
Here are a few pieces with this "elephant skin" glaze:
ref 60 007 & 50 011ref 20 050ref 70 015
To create this "elephant skin" enamel, I started with my white enamel, to which I added nickel in various proportions:
Samples 1 and 2 (red dot) caught my attention, so I kept these nickel concentrations. In this article, we'll follow the progress of the tests starting with sample #2. You can follow the progress of another glaze, which I've named "flesh", by following this link: (make link)
Tin oxide, as part of my white glaze, is a rather expensive raw material. According to the literature, it is possible to use zirconium silicate as a substitute. So I replace the tin oxide with zirconium silicate. I use the 2 nickel concentrations selected above and vary the zirconium silicate in two different concentrations:
At the bottom, we find the concentration a little more important. We get our slightly speckled look!
I continue the research with the bottom sample and proceed to a test on larger pieces to see the result:
Very interesting result!
I then perform a thickness test (To perform thickness tests, you will find an article here).
We confirm the results obtained previously! Thickness n°3 is the one that seems to me the most adapted to my future pieces.
To make this "cork" glaze, my starting point was my white glaze, to which I added iron in various proportions:
Samples 3 and 4 (red dot) catch my attention, so I keep these iron concentrations.
Tin oxide (part of my white glaze) is a rather expensive raw material. According to the literature, it is possible to use zirconium silicate as a substitute. So I replace the tin oxide by zirconium silicate. I use the 2 concentrations of iron selected above and vary the zirconium silicate in two different concentrations:
At the top, we find the low concentration of iron and at the bottom a slightly higher concentration. The lower tests give a brown color that I think is not very good, so I give up on that. On the other hand, the sample with less iron and more zirconium silicate gives me an interesting mottled glaze. I continue the tests from this sample (with the red dot).
I then proceed to a test on larger pieces to observe the rendering:
Here, I like the result! I decided to do a thickness test before adding it to my collection:
(link to build a small tool to measure the thickness of the enamel) :
To achieve this "iron yellow" glaze, I actually wanted to obtain an "iron blue" (you can read the article here, iron blue link). I did a triangle search in diagram 25 :
I take the sample 2nd line, first on the left (red dot), to do a search around an iron yellow :
I vary the iron oxide:
Taking the rightmost sample, I perform a search with the cross method:
I then select the sample on the left to perform a test on a larger piece:
Starting from the sample on the left, I try to add silica because the enamel is very runny:
The samples are then less flowing but not really usable, because the enamel is no longer fusible either.
I also test the thickness of the enamel, and it is, finally, this parameter that will solve the problems:
We notice that sample n° 2 does not sink and develops a nice yellow tressaillé.
I then carry out a test on a larger piece with a larger quantity of enamel preparation:
I find the results interesting, although I have yet to understand why the blue and crystallization do not appear everywhere or in every test. As with the "iron blue", I decided to carry out another test with sieving and another without, to see if this parameter could have an effect:
In view of the result obtained, which can be considered as identical on the three samples, I decide to redo a thickness test:
(link to build a small tool to measure enamel thickness)
The test is more or less conclusive. We notice that the enamel must not be thick, otherwise it's a disaster!
This beautiful water green glaze was discovered by chance! That's the beauty of searching for new glazes! Sometimes you discover things (often not aesthetically pleasing) but you get nice surprises from time to time. You have to try to interpret what you see and do new tests to develop a new glaze.
This one was obtained while researching my lichen green enamel. Indeed, this one seemed to me too runny. In order to make it more viscous, I tried to vary the presence of silica and I obtained this:
The result obtained with the most silica (red dot) gives us a blue green that is unexpected but not less interesting!
I'm trying to apply it to a larger room:
The color appears but in a rather disparate way, probably due to the method of application (brush). Indeed, by applying the enamel with a brush, it is often difficult to obtain an identical thickness on the whole piece. Here the color appears on the areas where the enamel is the thickest.
In order to understand a little better this enamel, we proceed to a thickness test (You have a small description of the manufacture of the tool here ):
We can clearly see that the first 2 layers do not show the green water. Thickness n° 3 is the one to try to reproduce. From 4, the glaze becomes runny.
The water green glaze obtained here consists for a large part of oak ash!
For this glaze that I call oil blue, I started from my oil red glaze. I added cobalt oxide in different proportions:
Very little visible, but a green and bluish color appears on the 2nd and 3rd samples.
I decide to continue my research with the cobalt concentrations of the first 3 samples and by varying this time the iron oxide, top cobalt at 0.1%, middle 0.5% and bottom at 1%, and from left to right from 5 to 9% iron oxide.
Close-up of the three samples at the bottom left:
On the 1% cobalt samples, the green/blue tint appears more clearly but the whole thing remains quite dark. I thought that, by decreasing the concentration of iron oxide, this oil drop aspect would disappear but it is not the case!
I start 2 tests in parallel: a cross method from the sample with 5% iron oxide:
... and I continue to lower the concentration of iron oxide:
The cross method does not bring us much, we notice that the tests remain very dark. On the other hand, the decrease of the iron oxide concentration makes this blue appear even more!
I then decided to test the 2 samples on the left on larger pieces to see the result:
I proceed to another test by lowering (again) the iron ox (sample):
Here, it is no longer what I am looking for, namely the oil drop phenomenon.
I take my formulas above and make a test by playing with the thickness (see here for the explanation of the construction of the tool):
In the middle I find the right thickness to show the stains due to the presence of red iron oxide ( see the article on oil red ). After testing this enamel with this thickness I get:
I specify that this enamel is all the more enigmatic because it is very difficult to take a picture. Indeed, in daylight it always appears much bluer than on the photos, I have tried many settings, point of view, camera ... it is very complicated to find the color of this enamel on the photos.
If we go back to the thickness test, I also find the enamel very interesting when it is applied thick! Unfortunately it is not topped. I could certainly increase my end of firing level but it would also impact my other glazes. That's why I prefer to keep the firing curve the same and work on the glaze composition. I am continuing my research and varying each of the components separately to see what can make the glaze a little less viscous in order to have a topping.
This test is very interesting, we see according to the raw material that we vary the impact of it. Here at the top, we find our control sample. On the second line on the right it is the sample with a little more Nephline Syenite. On the third line on the left, it is the sample with a little less kaolin. These are the 2 samples that appear as good as the control sample.
I decide to test these 2 on larger pieces to see if it's worth going further or if I stay on my control sample.
the test with more Nephline Syenite:
We notice that this test gives very similar results to what I had obtained initially.
The test with less kaolin:
By adding kaolin, we can see that the oil drop phenomenon appears much better. So this is the solution I will choose!
To obtain this lichen green glaze, my starting point was my first research with oak ash, thanks to which I obtained a transparent glaze. I decided to keep this same base and to add metallic copper oxides in different proportions:
We find the obtained tressaillage and we obtain moreover a green color. We can notice however a very runny glaze. To make the enamel less runny, I increase the ash content (top), then I increase the nepheline syenite content (bottom). The result is confusing:
There seems to be no difference between these tests... So I give up on changing the glaze constitution. Using my middle recipe, I try to apply this glaze on a larger piece:
The positive side is that I find the color and the braiding. The negative side is that the glaze is very runny and looks very impacted by the thickness since we can see unglazed areas at the top of the piece. The enameling of this piece was done with a brush, hence the important differences on the piece.
It is important to test the thickness of this enamel (link to build a small tool to measure the thickness of the enamel):
We can observe, as with my transparent tressaillé glaze, a flowing glaze when it is laid thick. The ideal sample is between sample 2 and 3.
As for the transparent version of this glaze, we can further highlight the cracks due to the braiding. For this, we proceed to the addition of Indian ink that will seep into the cracks.
To create this " Majorelle blue " enamel (the blue you find everywhere when you visit Majorelle's famous garden in Marrakech), my starting point was my white enamel, to which I added cobalt in various proportions:
Sample 4 (red dot) holds my interest, I keep this cobalt concentration and I vary the tin oxide used, in principle, to mattify the enamel:
The impact of the tin on this glaze is clearly visible. The glaze becomes more viscous (less flowing) when tin is added.
Tin oxide is a rather expensive raw material. According to the literature, it is possible to use zirconium silicate as a substitute. I replace the tin oxide with zirconium silicate and vary the proportions in order to compare the matting power of each oxide:
Indeed, after comparing the results, zirconium silicate brings a similar effect to tin oxide. So I choose this option. I select the second to last sample (red dot) and test it on slightly larger pieces:
I'm happy with the result! This enamel joins my collection!
In order to obtain this transparent glaze with braiding, I started a research around oak ash, mixing, in equal proportions, oak ash and Nepheline Syenite, while adding silica in different proportions:
The sample on the bottom left contains the least amount of silica. I decide to continue to lower this rate and then, when it is zero (top right sample), I proceed to an addition of alumina through kaolin to observe the reaction:
I select the sample (top left) where we can see a beautiful crackling (crackling of the enamel due to a difference in expansion between the enamel and the shard).
This enamel seems satisfactory, I decide to try this enamel on a more important piece:
I then get a nice tressaillage. I will continue my research by adding metallic oxides to this glaze which you can follow in other articles. I will also do a thickness test (see here for the explanation of the tool construction): with this transparent enamel:
We can see that the glaze is very runny if placed thick. The second sample corresponds to the thickness that we will try to reproduce. This is to obtain a nice braid without too much flow.
And one last little trick to bring out the tremor on the piece: we add Indian ink to the brush on the piece. The ink will seep into the cracks. Once the ink is dry, simply clean the ink from the surface of the enamel. And you get a great effect. I have done the operation on the back of the sample 2 above:
