Head of Christ Stained Glass - project 2

HEAD OF CHRIST LORSCH ABBEY GERMANY AND ABBEY CHURCH WISSEMBOURG ALSACE STAINED GLASS PROJECT 3 - Liz Gerald December 29, 2012 


NOTES: 

 I have decided to put a bibliography at the end of the blog rather than clutter up the blog with complete references. I will reference the title of the book, one authors name and the page in the blog - all other info will be at the end.

If I have described the medieval methods in previous blogs, I will not repeat the medieval methods again unless they work better than modern  methods or unless I am retrying then to see if I can get them to work.


UPDATE HISTORY:

December 29 2012 - various pictures of this piece, some of the history, doing the design,  picking the glass, Chalking the "board",
December 30, 2012 - doing the design, outlining the design, cutting out the head, using grossers, setting up the sketch and the glass cut out of the head for tracing.
December 31, 2012 - Update on my chalk experiment,  trying to make my own black trace paint, doing the trace outlining of the head.
January 2, 2013 - results of the trace firing, redoing the trace lines and refiring, designing the pattern around the head.
January 3 and 4, 2013 - shading of the face, caming, soldering, cementing.
January 7, 2013 - final product!

HEAD OF CHRIST LORSCH ABBEY GERMANY AND ABBEY CHURCH WISSEMBOURG ALSACE

The picture below is from Stained Glass by Lawrence Lee,  page 13 - the caption with it is " Excavations in 1912 at Lorsch Abbey in Germany unearthed fragments of stained glass which are thought to date from the ninth or tenth century. In spite of the dark gaps of missing glass, a head of Christ is suggested by this reconstruction of the ancient pieces, believed to be the earliest existing pictorial stained glass"

 This same book on page 38 has another version of a Christ head.  The caption on that page states "Austere yet hypnotic, the expression of this eleventh century face of Christ is created by a design of ornamental simplicity. Originally in the  Abbey Church of Wissembourg, Alsace, it is now in the Musee de l'Oeuvre Notre Dame, Strasborg and is the earliest stained glass image to have survived intact.

Another picture of this same Christ head from Glass Painters Sarah Brown page 9 below has a caption that states "This austere eleventh century head, probably of Christ, perfectly demonstrates the three- layered tonal style of painting described in Theophilus' treatise De Diversis Artibus.". This picture also shows a "reddish" area around his shoulders which I have not seen elsewhere.

WHAT MY DESIGN WILL BE

My design will be a combination of both Christ heads. I like the white glass around the first one and the second one has clear detail that I can replicate.

GLASS THAT I WILL BE USING

I have not picked out the white glass.  However it will probably be a white/clear streaking spectrum glass. The glass that I have picked out for the actual face is Uroboros UR 60-00-96F.  I picked this as it is a glass with alot of natural "defects" in it such as bubbles, streaks and creases.  I feel that it is probably similar to the glass that would have been produced at that time versus the really smooth window glass that we have now.  I have picked clear as I will be doing the brown highlights to get the affect above. Below is a picture of the clear glass. It is a little hard to see the imperfections but as we go along during the different steps you will be able to see them.

CHALKING UP THE BOARD


In On Divers Arts-- Hawthorne - they have Theophilus describing how the board that the glass piece will be done is prepared. He states  "when you want to lay out glass windows, first make yourself a smooth flat wooden board, wide and long enough so that you can work two sections of each window on it. Than take a piece of chalk, scrape it with a knife all over the board, sprinkle water on it everywhere, and rub it all over with a cloth." [page 61]

Well this sounds pretty easy! I went out to my shed and got a piece of plywood. I went out to the local craft store and bought white chalk.  Using a knife, I flaked off chalk onto the wood as shown below:

I than wet it with water....

And it basically completely washed away.....not the desired result....Solution???? Why he must have used much more chalk than I did.  So put a "ton" of chalk flakes on the board as shown below:

And then wet with water....

Result?? Nice globs of chalky mess.....

THOUGHTS:  Maybe plywood was not a good wood to use.  Try another time with another wood.  Can our chalk properties be different than medieval times?  Will have to do more research on this.  So much for "chalking": up the work board!


December 30 2012

THE DESIGN:

Since I am not a real good free style artist of faces, I decided to use my light box to sketch the basic outline of the face from Wissembourg.  See below for my pencil sketch that will be the basic design. I will be drawing the rim of white glass around the head in a later sketch.

I than took the glass and outlined just the basic outline of the piece

I will cut out just along the the black trace mark

In On Divers Arts Hawthrone, Theophilus describes this process as such " now take a piece of glass of whatever kind you have chosen, but larger on all sides than the place in which it is to be set, and lay it on the ground for that place.  Then you will see the drawing on the board through the intervening glass, and following it, draw the outlines only on the glass with chalk" page 62

CUTTING AND USING GROSSER PLIERS

I have taken the outline and cut it using modern methods, steel hand held cutting wheel.  I got out my grosser pliers, that nibble at the edges which are outside of the outline after cutting.  I saw a reference that stated the rough edges on medieval stained glass were the result of using this tool.  If I can find that reference again I will insert it here.  I do dispute that finding as after firing painted pieced the edges start to take on a very smooth edge depending on the times that they are fired.

The series of photos below show the glass head with a piece of glass outside of the outline, the grossers on that piece and then then final version of that area...still not perfect.

I continued to do this process on any of the glass that fell outside of the outline.

SETTING UP THE HEAD FOR TRACING

Now we have the "board with the sketch on it" - I have the pattern on a white piece of paper, and the glass head cut out to size.  This needs to be position so that the sketch can be seen through the glass while being worked on to put the black tracing lines on.  the clear glass.  I have seen some references that they might have used beeswax to set the glass on the sketch while they worked.  So I have used that process as shown below: First I dripped a few drops of melted glass onto my sketch

Than I put the glass head cut out over it.

What did I learn...the wax cools very fast so you have to be fast at doing this or it won't stick! The spots are the wax between the back of the glass and the sketch.

UPDATE ON THE CHALKING OF THE BOARD

A dear friend read my blog and saw that I had an issue with "chalking" the board.  Being a great researcher she looked into modern day blackboard chalk properties - which is what I used.  She found out that blackboard chalk is not actually chalk but it is usually made from the mineral gypsum [calcium sulfate].  So this may be the reason why I could not replicate the medieval process with the blackboard chalk.  I will have to find "real" chalk and try again!

EXPERIMENT ON MAKING MY OWN BLACK TRACING PAINT

Now I figured that I would try to make my own black tracing paint.  Theophilus in this book On Divers Arts Hawthrorne describes making this paint as such " take copper that has been beaten thin, and burn it in a small iron pan, until it has fallen into powder.Then take pieces of green glass, and Byzantine blue glass and grind them separately between two porphyry stones.  Mix these three together in such a way that there is one third of [copper] powder, one third of green and one third of blue.. Then grind them on the very same stone very carefully with wine or urine" page 63


Well I had a couple of issues with material on this one.  I did not have the green or blue glass but I did have confetti black bullseye glass.  That is glass shards almost like mica.  Also I did not have wine and did not want to use urine.

Also I did not have porphyry stone which is  a volcanic stone that was cooled in horizontal and vertical layers that makes it an extremely hard stone.  I only had a wooden mortar and pestle

Lastly, I don't understand why Theophilus has no mention of a binding agent like gum arabic which was available in that time frame.

However I decided to give it a try.....


These are the black bullseye confetti chips:

I put them in my morter and pestal and ground

And I ground them.  What I noticed is that the wood was soft and did not want to reduce the glass into a fine powder.  There were very small chips in the final product.  However it did not look that much different than the powdered Reusche tracing black paint powder.  My batch is the smaller of the two mounds.  I did notice that my batch also has some white powder in it when I ground up the glass. Is this an additive in this type of glass?

I than added gum arabic to both

And mixed it in well

Than I applied water to the batch that I had ground up. It became a mud like consistancy and the other thing that I noticed is that it would not stick to the knife

I mixed water in with the Reusche paint and the is the correct consistancy and does stick to the knife.

THOUGHTS? Obviously I have to do alot more experimenting with this!!!! Will get some porphyry stone from the local box hardware store, will get wine, and  instead of using the mica type glass, I will take some standard black glass next time and grind that......

DOING THE TRACING LINES OF THE HEAD

Using the Reusche paint, I traced the lines of the head from the drawing.  Now one thing that I noticed is that I was having a real hard time getting the finer detailing lines done especially in the hair.  After removing the wet paint several times, I decide to put on extra paint and then remove it with a wooden tool [ a toothpick], which is a process that was used in medieval times and I can see why. Below is the rough trace lining of the head. 

After it dried I took my toothpick and cleaned up and defined the lines.  See below for the head that is ready to go into the kiln and be fired.

January 2, 2012

FIRING THE TRACE LINES

I put the head in the kiln and fired at high until it reached 500F. I turned off the kiln to let the glass soak for 10 minutes.  I turned the kiln back on and got distracted with a phone call....As a result the kiln got to 1500F and proceeded to burn off some of the paint.  See below.  NOTE TO SELF:  Do not answer the phone when firing in the kiln!!

I redid the head on a new piece of glass and refired up to 1400.  I did not take any phone calls this time.  I did notice  that some of the trace burned off.  I may have to experiment with a lower temperature. The Reusche tracing black paint that I am using says to fire between 1150 t0 1400F.  I will continue to use this head as I want to get this piece to finish for an event that I am going to this weekend.

DESIGNING THE PATTERN 

I designed the rest of the pattern go around the head.  I incorporated the "halo" design from Lorsch Abby Jesus head. And then have squared it off so it will fit in a frame.   The glass in the "halo" appears to be a white but it has streaks and even brown marks.  Possible impurities?  I will be using a streaky white spectrum and then a wissmarch blue to square the corners.

This is the white that I will be using. It is as close as I can get from what I can see in the picture.

Tomorrow I will be doing the brown matting on the face and firing it again.

DOING THE SHADING OR DETAILING

 Theophilus states "when you have made the painted areas in robes out of the above mentioned pigment, smear it about with the brush in such a way while the glass is made transparent in the part where you would normally make highlights in a painting, the same area is opaque in  one part, light in another and still lighter[ in a third]  and distinguish  with such care that there seem to be , as it were, three pigments placed side by side.” [i]

I will be using Reusche Bistre Brown, an application brush and matting brush to achieve the shading technique.

I mixed the paint, water and gum arabic and applied it to both faces.  It went on very thick. When it dried, I found out that I could not remove the paint with a brush, so I had to wash it off and start over. Either I did not use enough water or I used too much gum Arabic.

I made a second batch of paint with more water and less gum Arabic. It went on much thinner and could be brushed off after drying to get the shading effect. I put the finished head in the kiln.  I changed the firing to be high until 1400F degrees.  I did not shut it down to soak at 500F degrees.

SETTING UP THE BOARD TO DO THE CAMING

In Medieval times, they would have chalked the board up to outline the shapes of the pieces to cut and they would have used the same board to build the actual piece up on.  I am going to use a piece of paper with the cartoon/design taped to the board.

  
   

WHAT IS CAMING?

Caming is the process of using a lead material to outline the glass pieces and then using that lead material it forms the basis of the joint to solder the work together so that it does not fall apart.  “The idea of using a framework of lead to hold together the pieces of glass may well have been inspired by the art of the goldsmith and the cloisonné enameller. Imagine, for example a man watching a goldsmith work…knowing that colored glass could by the Middle Ages, be made in reasonably large pieces, he suddenly suddenly thinks of lead instead of gold – a cheap and malleable metal, which could hold a pattern of glass panes as a jeweled window rather than as a jeweled brooch”[ii]

TOOLS NEEDED TO DO CAMING

Tools needed are cutters.  There are modern day came knifes which are very similar to linoleum knifes.   I use lead cutters so that is what I will use for this project. In future projects I will get a knife to experiment with as that would be more period to the medieval methods.

Also needed are nails and a hammer to hold the pieces together as you build up the window. Theophilus describes these nails as "you should have forty nails, a finger long, slender and round at one end and at the other square and bent well outward so that a hole appears in the middle". [iii]  Since I don't have these exact nails I am going to use the nails that are used in modern work - commonly referred to has horse shoe nails.

 

WHAT IS CAME?

“The strips of metal used by the cloisonne enameller to enframe areas of coloured enamel are, with their raised outlines, even more suggestive of lead lines in  stained glass window....Another important discover was linked with the invention of casting, or milling, a strip of lead with a section that could be shaped and jointed to hold glass in a transportable panel."[iv]

Theophilus in On Divers Arts has a chapter devoted to the casting of the cames.   This is not something that I am able to do so I have purchased the formed came.  I will be using what is called a H came - this is came that can take a piece of glass on both sides.   I am using 3/16" H.  The U came that I am using can only take glass on one side and is used to outline the piece.   I am also using 3/16" U came.

APPLYING THE CAME


Theophilus describes the process of putting came around the glass pieces by saying - " take the painted and fired glass and lay it in its order on the half of the board where there is no drawing. After this take up the head of a figure, wrap a lead came around it, and replace it carefully[on the drawing on the first side of the board]. Then drive in three nails around it with a hammer suited for this work and fit to it the breast, the arms, and the robes that remains. As you set each piece in position, secure it with nails on the outer side so that it cannot move from its place" [v] This is the  same process as done in modern glass work with one big difference.  In modern glass work the artisan tends to work from a corner and goes out.  They do not tend to work from the center of a design. I have set up my board with the glass pieces and have done the first piece – the head - below.  Next to that is the entire piece camed.

SOLDERING THE CAME

Theophilus states “when you have finished everything…take some pure tin and mix it with a fifth part lead, and in the above mentioned iron or wooden mold cast as many sticks as you want for use in the soldering of your work…..Now you should have a soldering iron that is long and thin, with a thick round end drawn out to a slender  point and filed and tinned. Put this in the fire. Meanwhile take the tin sticks that you have cast and pour wax on both sides.”[vi]  I am not going to make my own solder sticks. I will be using 60/40 tin/lead solder.

Theophilus continues “scrape the surface of the lead cames at all the places that are to be soldered.  Pick up the hot iron and, wherever two pieces of lead meet, touch the tin to it and smear them with the iron until they stick to each other….when the window is finished and soldered on one side, turn it over on its other side, scrape and solder it in the same way, and secure it firm throughout.”[vii]

I used a came brush to clean the joints. I also use a flux to help with the soldering. I cannot find a reference for flux in medieval times.  Below is a picture of the front soldered.

CEMENTING THE PIECE

Theophilus actually never talks about cementing although I am sure that this was done. I will have to do  more research on this. I used  a product  called Miracle Mudd – which is a two part mixture.  You take the dry black powder and mix with the liquid binding agent.  You put this on the piece.  Than you take a brush and brush the mixture into the came.

Next you take a product called whiting which absorbs the moisture and helps to set the cement.

THE FINISHED PIECE FRAMED

I  wanted to put a frame around this piece that would be reflective of where it would have been displayed...in a church nave.  I went to  my local home improvement store and bought a lighter colored tile with sandy colored grout.  This was the first time that I have ever tiled.  I built a wooden frame for the piece and then grouted the tiles to get the result below.

I hope that you have enjoyed my second journey into the world of medieval stained glass!  I will be starting up my third project - a replica Gathering of Manna from the original in the Cloisters in New York.  I will also be doing a non painted replica of an Anglo Saxon window.