After grinding white it becomes a finer powdery texture.This is used to mix with other dry pigments when making tints of colors.Another white pigment,titanium dioxide is also used,but pure lime white seems to be more brilliant.

Dry cakes of lime putty being crushed into white to use for painting.

The same lime putty that was used to mix with sand to make plaster,is also used to make a white pigment.Wet putty such as in this photo is formed into lumps,and allowed to dry.It is then crushed with the mueller until it has the same texture as dry pigments.

This photograph shows the process of grinding dry pigment into a paste for paint.The pigment used here is indian red.The same color used in the dry panel in the photograph above.The glass tool used to grind the paint is called a mueller.The flat bottom of the glass has a slightly rougher texture,like etched glass.Pigment is first poured onto a peice of glass,then the mueller is used to crush it into fine particles.After crushing,a side to side motion is used to make the pigment as powdery and uniform in texture as possible in preparation for making it into paint.If the particles of pigment are too coarse,not ground finely enough the lime plaster doesn't absorb them effectively,and the aesthetic result may not be pleasing.

These panels are dry,showing the difference between cadmium red,and indian red.The panel on the left,cadmium red after reacting with lime,becomes more pink than true cadmium red pigment.Indian red pigment starts as a dark,earth tone red similar to terra cotta clay.After being painted onto lime plaster it turns into a lighter,violet tone.This color when mixed with white,can be used for flesh tones.It appears a true cadmium red in fresco would only be possible in secco.This means painting another layer of it over the dry color like these panels,to make it more vibrant again.One of the biggest limitations with fresco painting seems to be the restricted palette of colors and value scale possible with only the direct technique.

Another experiment involves allowing the marks in wet plaster to be visible when dry,then staining the final panel.It would be possible then to paint with stains on the dry plaster.It would also be possible to incise line,then allow darker pigment to fill it,as a form of drawing.Experimenting with mark making allows the physical movements of the artists hands while painting to be seen.

In contrast to the cobalt blue paint which separates from the water,the yellow ochre pigment in the jar in this photograph next to the green tube of paint,leaves the water tinted yellow,even after both have settled overnight.

This jar shows the cobalt blue pigment in the form of wet paint.This is a good example of how different pigments have different physical reactions.This blue pigment separates when dispersed in water.

This jar shows the pure cadmium red color while it is still wet.

These panels show a yellow ochre paint and a pure cadmium red,during the drying process.The paint first goes on very dark and saturated,and as it reacts to the lime,as seen in the photo,lighter streaks begin to appear.

Some of the sample colors,I photographed in various stages.From the mixing of the pigment with water,and the addition of lime putty,to the various drying stages.I then labeled the back of the panels with the name of the pigment used.By premixing colors with water,adding the lime and storing them in glass jars under a layer of water-I am able to see the color of the paints while wet,and after reacting with lime.This way I have a more true idea of how they will actually appear when I use them to make images.By making the test panels of various colors I can then compare the dry color on the board,to the wet color in the jar.This should give me more control over the value range in the finished paintings.Shown here are panels of indian red and yellow ochre pigment,on wet lime putty,before drying.

This image shows the liquid tube watercolor cobalt blue hue applied to the lime putty before mixing.The original darker tone can be seen,the lighter blue dry panel above is the cobalt pigment after reacting with lime.One of the difficulties with fresco painting is that every pigment reacts differently with the lime.Some appear darker on application and dry much lighter,some absorb more and are more saturated,some colors grab darker.It can be described in some ways as painting into the future,as I can't paint with what the colors currently are as they are applied,rather I have to imagine what they will be once dry.This proves to be very difficult as there are so many factors involved,such as what happens when colors are mixed using the addition of white,or with two or more pigments.Some pigments will dominate others.This also makes obtaining a value range difficult.In order to render images effectively,control of light and dark is very important.So I began to experiment with making smaller panels of various colors to teach my eyes to recognize how the pigments will change.

The grey-green color is more visible in this photo as it reacts with the lime it first darkens then lightens as it dries.Lime plaster doesnt actually really dry,it undergoes a process in which the lime reacts with carbon dioxide in the air and hardens back into limestone.When pigments are dispersed in water and added to the lime while it is still wet,or open,the colors are then bound into the lime and become part of the surface.Unlike other forms of painting,such as oil or watercolor which form films on a surface,with fresco,colors are integrated and become part of the surface itself.This process plays a role in the unique way the color of fresco is reflected to the eye as well.There is a luminous quality to the colors in fresco because of the way light reflects on the lime,the quality of the color of white of lime putty is unique.It is different than the way color is seen in other types of paintings like oils,in which the white ground is reflected back through the various layers of color to the viewer.Fresco has a more chalky calcium white type of finish,somewhat like seashells.

On another panel with a dry scratch coat,a thicker tinted lime plaster was applied.The pigments experimented with were a mixture this time,of cobalt blue,viridian green and mars black liquid tube watercolors.It created a greyed down turquoise green.While grinding dry pigments with a muller,and making several combinations of colors,and test panels,I wondered if a more intense color would be possible with a liquid pigment.Since watercolor paints are basically the same as fresco paint,with the addition of a gum binder,in theory it should work.I expected the lime would be caustic to the gum binder in watercolor but if the paint was based in earth pigment,it would be essentially the same as if I had ground the dry pigment myself.Since a range of dry pigments are more difficult to find in art supplies than watercolors,and are more expensive,I wanted to try experimenting with this,and various combinations of watercolor and dry pigment.

Another experiment,I applied a wash of lime paint,a thin mixture of water,lime and pigment,to the panel while still damp.It gives a watercolor wash effect,while also highlighting the sandy texture.This wash was applied with a brush,poured on and wiped on with a cotton cloth,all to varied textural effect.

This panel shows the color after drying for 24 hours.Cobalt blue pigment is the color of this text.When mixed with lime after drying it lightens several shades to something closer to this color

The texture of the plaster and the marks of the palette knife were allowed to stay visible.There are several ways to use a panel like this,when dry,I can paint over it in secco techniques or use digital processes,or while still wet,I can paint on it with various color pigments in the traditional technique.

After the scratch coat has dried,a second application of plaster is applied.This is an experiment with a tinted coat of plaster.Traditionally,white lime plaster is painted on directly while still wet,with a paint made of ground pigments and water.Distilled water and lime safe pigments must be used in fresco painting because chlorine from tap water will bleach the colors.Since lime is alkaline,it already reacts with the colors,typically only earth pigments are stable in lime,other pigments will bleach outAll colors tend to fade significantly while drying in reaction to the lime.A particular difficulty is working with blue,as ultramarine is not stable in lime.Cobalt blue is,but it is toxic and wearing a dust mask is particularly important.As such blue colors were traditionally painted after the fresco dried,with egg tempera,the same pigment and water with the addition of the binder of egg yolk.This color sat on top of the fresco and does not bind with the lime and therefore is not as permanent and may flake off.This experiment was to see if tinting the plaster directly,with a liquid cobalt pigment would help maintain a saturated blue color.

After the plaster is applied to the panel,it is scratched with the tip of the palette knife.This first coat is called the scratch coat or brown coat in English plastering terms,or in Italian,arricio.Drying times vary with the environment,temperature,humidity,air circulation all play a role.

The untinted plaster with sand is applied to the boards with a palette knife.

The addition of sand to the lime putty adds strength and prevents cracking.It also helps provide a tooth to adhere to for the second smoother coat of plaster.The texture of the sand does not have to be visible in the final image,as each later of plaster uses progressively finer sand.I'm experimenting with allowing the texture to show in the final image as well as allowing the marks of the tools used to show,as in the impasto oil painting technique.Traditional fresco calls for a smooth surface,experiments with digital media and traditional fresco,as well as combinations of fresco and secco techniques caused me to try some experiments with texture as well as how and when pigment is added to the plaster,for various effects.

The panels are prepared with an application of lime plaster.This photo shows lime putty aged for 3 years,placed on a surface for the addition of sand.Lime putty alone would crack if applied to the boards without the sand.It has the consistency of sour cream and no odor,but is alkaline and prolonged contact with the hands must be avoided.

The first step is preparing several boards for the fresco surfaces.I've started with 20 4 x 6 boards,and 10 18 by 24 boards.This photo shows the 18 by 24 size before the application of the scratch coat,or first coat of lime plaster.