10 per cent crimson, 3 per cent oxide tin, 15 per cent white lead, 6 2-3 per cent paris white and 65 1-3 per cent lead glaze will make a crimson glaze.

Matt Blue. Fire Very Hard -

 

Aluminate of Potash ............................

33.80

Hydrate of Alumina ............................

11.27

Oxide of Zinc .....................................

22.54

Flint ............................

16.90

Nitrate of Potash .................................

9.86

Oxide of Cobalt ...................................

5.63

 

100.00

Grinding and firing again will improve. This is a much simpler method than the ones usually given for Matt Blue, and produces fine results.

Matt Blue, No. 2. Very Hard Fire -

Hydrate of Alumina .................................

73.40

Oxide of Zinc ..........................................

18.35

China Clay ..............................................

2.75

Oxide of Cobalt .....................................

5.50

 

100.00

   

Mazarine Blue. Medium Easy Fire -

Paris White ..................................

16

Red Lead ...................................

10

Flint ............................................

10

Nitrate of Soda ..........................

4

Oxide of Cobalt ........................

60

 

100

This is a very strong blue.

Blue, No. 1. Fire Hard -

 

China Clay ............................

40

Oxide Zinc ...........................

20

Flint ....................................

10

Nitrate of Soda ....................

10

Oxide of Cobalt .................

20

 

100

There are so many ways of making black, each suited to the particular situation, and, possibly, not to any other situation, that it is useless to give receipts. Chromate of iron (native), from 80 to 98 per cent, with oxide of cobalt, from 20 down to 2 per cent, will make black under proper conditions. Albany slip clay and cobalt, iron and cobalt manganese and cobalt will make black. These blacks will have a brownish, bluish or greenish tinge. If the business will stand a cost of $60 to $150 per pound for black, it can be made from iridium, but usually it is better to be content with a slight tint in the black. A deep blue glaze over red slip clay will make a Jet black when the depth of color of the red and blue are properly adjusted. Use a mazarine blue stain for making the blue glaze. If the brightness of the blue is killed by adding a little iron, copper or manganese to the blue glaze the result is usually better. Grays are the same as blacks. Copper, manganese and cobalt will make blue grays, green grays or brown grays, depending upon the proportions. Chromium, iron and cobalt will give a very pretty series of grays in light tints. Buff clay and cobalt or buff clay, manganese and cobalt will yield good grays. Chromate of iron (native) and cobalt will yield good grays from light to very dark, but for really fine high heat neutral grays we have to turn to platinum.

The high heat greens are usually made from chromium in some of its many forms, the lower heat green glazes from copper. The black or red oxide of copper can be used direct in glaze without previous burning.

Green, No. 1. Hard Fire -

 

Flint ............................

40.70

Paris White ....................................

4.42

Borax ..............................................

10.62

Oxide of Zinc....................

8.85

Plaster of Paris ...............................

10.63

Bichromate of Potash .....................

22.12

Oxide of Cobalt...................

2.66

 

100.00

Green, No. 2. Grind Only—

 

Green, No. 1 ..............................

94

Oxide of Cobalt .........................

6

 

100

Green, No. 3. Hard Fire -

 

Flint ............................

31.67

Paris White ...................................

20.28

Red Lead ......................................

8.87

Plaster of Paris .............................

7.61

Fluor Spar ...................................

10.02

Bichromate of Potash ................

21.55

 

100.00

Green, No. 4. Hard Fire—

 

Oxide of Zinc ..............................

14.81

Flint ............................................

37.04

Borax ........................................

18.52

Oxide of Chrome ......................

22.22

Oxide of Cobalt .........................

7.41

 

100.00

Green, No. 5. Hard Fire-

 
 

20

 

15

Flint ...........................

25

 

40

 

100

Green, No. 6. Hard Fire -

 
 

29.00

 

28.12

Oxide of Nickel..................

28.58

 

14.30

 

100.00

Green, No 7. Hard Fire -

 
 

6.78

Oxide of Zinc.....................

40.68

 

40.68

 

1.69

Oxide of Cobalt..................

10.17

 

100.00

Green, No. 8. Hard Fire—

 
 

22.22

 

22.22

 

27.78

 

11.11

 

16.67

 

100.00

The shade of green can be altered by addition of cobalt— that is, made more blue - and can be deadened by adding a little manganese.

The browns are nearly all derived from combinations of iron and chromium or from manganese. The chromium may be used as chromate of potash or oxide of chromium, and the iron either as iron scales or oxide of iron. These, when combined with oxide of zinc, produce the lighter or claret browns, and, when combined with fluxes, produce darker browns. The browns can be mixed with the chrome pinks to advantage for red browns.

Cobalt will mix with the chrome reds and pinks, producing purples.

In experimenting with colors, after having perfected the white, it is undoubtedly better to buy the stains in the form of underglaze colors rather than to bother with making them. After certain tints are secured, then it may be well to learn how to make the stains for their production, but even then, if the business is one requiring constant new colors, and there is no certainty that there will be a constant demand for any one of them, it pays better to buy stains than to make them. Of course, if there is a constant demand for certain colors, then it pays to make the stains. A pound of crimson stain will cost about one dollar and a half, and it can be made at a cost for materials of about 13 1/2 cents, but by the time a few pounds are mixed, then burned and ground, and the second mix made and burned and ground, there is very little advantage in making it If made by the hundreds of pounds it would pay handsomely. The large number of color mills necessary where stains are made, or else the constant and careful cleansing of a few, is quite a source of expense. On paper it looks very profitable to make the stains, but in reality it is not, unless, as I have said, there is a constant demand in fairly large quantities.