Period Vitreous Paints, pt 1: Oops, this worked?

"...using for this ground scales of iron and of another rust found in iron pits, which is red, or else hard red haematitefinely ground, and with these pigments he shades the flesh, using alternately black and red, according to need." - Vasari (Dover translation p. 269)

"...and he gives you a color which he makes from well-ground copper filings;" -Cennini (Dover translation p. 111)

"Take copper that has been beaten thin and burn it in a small iron pan, until it has all fallen into a powder. Then take pieces of green glass and Byzantine blue glass and grind them separately between porphyry stones. Mix these three together in such a waythat there is one third of [copper] powder, one third of green, and one third of blue. Then grind them on the same stone very carefully with wine or urine, put them in an iron or lead pot, and with the greatest care paint the glass following the lines on the board." - Theophilus (Dover translation, p, 63)

Since I've made all but one of the period silver stain formulas I have found, I've decided to try and make vitreous paint. I started by building a frit smasher; it's not the period way to grind glass but it is infinitely easier for some initial tests.

Vasari seems to suggest you just paint with metal dust. Cennini is less specific, but doesn't contradict that. Theophilus clarifies a mixture of metal filings and glass, one part to two..

Just as with my silver stain tests, where I started off with purchased silver salts, I used my frit smasher (aka a frit piston) to smash pieces of scrap clear glass from my scrap buckets. I originally thought that this would require making paints from the same glass you are going to paint on, but nothing in the primary sources suggests that. I've seen reference that say modern vitreous paints are more "glass fluxes" and oxides, rather than actual glass; the latter would seem to be more akin to an enamel as we define it modernly. In this case I specifically sought out pieces from at least two different original sheets to avoid accidentally lining up CoEs.

Scrap glass pieces. I ended up using about twice this. My left hand for scale.

After just a few minutes work, with occasionally shaking of the pile to mix it up for better smashing

For those who don't do much with warm or hot glass, the Coefficient of Expansion relates to how quickly the warming or cooling glass expands or contracts. If you try to use two pieces of glass with incompatible CoEs, they will separate, usually fatally and sometimes explosively. I've generally seen a safe range being only one point in either direction (the common CoEs are 90 and 96 for fusible glass, with 103 also being common to lampworkers making beads. Borosilicate glass/Pyrex used by some lampworkers is CoE 33.) The bulbs I use for my ornaments class are COE 89; we use CoE 90 frit with them with no problem, but 96 is right out.

I rather expected the CoE would be a problem, and would spall or destroy the test chip. I used my frit smasher and generated a mess of pebbles and dust. Lacking anything more specific for filtering, I rolled the material in a piece of cheesecloth to get a grainy powder into a bowl.

Do not inhale this!

I ended up with a wooden bowl of rough clear glass powder. I turned to two purchased bags of metal filings, one iron and one copper. Bother are already a very very fine powder. I scooped a little of each into small wooden bowls using a palette knife, and added a similar amount of glass powder. As I stirred I worried there wouldn't be enough glass to "bind" the metal, and I added more of my clear powder. I ended up, accidentally, with approximately the ratio Theophilus called for. I did some cursory grinding on the palette, but it really didn't help. Testing it with a sable brush showed poor adhesion to the hairs, and the paint that left the brush was fairly poor, very weak with the copper-based batch. The iron batch was much better. As both metals are finely powdered I think I found a better portion of the powder bowl to draw from by luck.

Next go around, I will try to grind them up on porphyry, as period sources call for. I have been confused from time to time on what that means. Over Facebook THL Ian the Green gave me some clearer details from C&I pigment creation. He referenced this video, suggesting the technique at 6:29 and after 8:00 would be helpful. I will try and follow these next.

I placed them on some of my standard test chips, cut to size a binder full of test chips. Because it is glass powder and metal, I suspected that it would require a fairly high temperature to fire these paints; period sources definitely don't have the precise control we have, and in theory this strikes me as much more akin to glass fusing than normal paint firing. I used my standard cycle (which reaches 1250) and waited. And waited. And WAAAAITED.

The chips actually worked quite well. They didn't fire to the smooth and glossy shine of my modern Resuche paints, but they were opaque and well-adhered. I suspected, still, that they would be poorly fixed so I took the chips to my lightbox and hit them with a skewer I use for cleanup work. None of it scratched off.

The iron chip is "psychologically black" rather than optically black; When you see it, you know it's black. Your brain would remember it as black. It's actually fairly grey. The copper based pigment is a pretty color, but I would best describe it as somewhat like dried blood; It's lighter than bistre brown (which reminds me of old tree bark, it's a very dark color but not enough to be perceived as black) and it's a bit darker and more true than tracing brown, which to me has a reddish hint.

Overall, it was incredibly exciting to get working results with these very first attempts. I'm going to pursue more period steps immediately.

As an afterthought, I want to document something Master Avery shared on Facebook. I was totally unaware that you can reverse rust back into iron. The physical structure is destroyed, but the iron is recoverable. This is one way to get good, fine, filings; By using an oxidizer (and I will edit in what he offered, bleach I think) you can get the iron to rust. Then you can easily grind the rust. Putting it in charcoal and heating it appropriately will reverse the oxidation and leave iron. Very, very neat.


Lessons Learned/New Questions:
Holy cow, this worked.
It would work better if ground up more finely
     Use commercial powder/better sieved home made powder?
     Try the porphyry method
Does da Pisa have a recipe? Mappae Clavicula? The Bolognese manuscript? Have to check them...
I did very tiny batches, next time use my sandblasting mask to avoid any invisible dust inhalation.
How is color modulated? How is my modern tracing black so much darker? More iron? Or a darker mineral?
What will hematite look like? Pinkish, for sure, but...
What is Byzantine blue glass? A color, or a specific formula of glass? Byzantium is a purple...

Frit smash Smash SMASH!

A very short post, but I was looking to make frit (powder, specifically) for an upcoming project. I didn't want to buy one, I wanted instant gratification. I found these directions from Delphi Glass and went to my local hardware store for the parts (admittedly after googling to figure out what nipple pipes were... I thought it must be a typo!).

I added one step, in that I had a jar of BBs (for a BB gun) laying around. The smaller pipe, which does the work, I filled to the brim with tiny steel BBs. I had also purchased a second cap for it, adding a buck to the cost. I think the added weight was a great idea.

I put a small piece of clear in the smasher, and dropped the weighted pipe on it three times. What I poured out was almost small enough to be used for lampworking/fusing. I was very surprised how quickly this thing works. I think it needs more glass to get truly effective, and it'll be fun to experiment with to making powder for glass paints.

The two pieces of my frit smasher; you can see the operating end covered in glass dust

Two Ayreton Stars

The lightbox, at the moment

The muse sang so I danced. I've cut two Ayreton Populace Badges to whip out in a hurry and give to the new TE Ayreton. They aren't actually done, but I think the lessons portion is done, and there are a few lessons learned! I'm writing this up early and will follow-up with a completed picture in a day or two.

I was originally going to do one "swirl" and one "straight" but cut them both swirled, and I have no regrets. As soon as I finished cutting the first I thought those straight lines would be SO BORING and amateurish (not that anything with 12 pieces is particularly fancy!) unless I found the perfect bevels.

I cut the pieces for the first one out (the one laid out, top right corner), and set them on the pattern. And then I freaked out. They weren't fitting. AT ALL. Not even close. For a change of pace, and a bit of experiment, I decided to do these by cutting out the pattern with shears and tracing them onto the glass. How could it be that wrong?! I had a mini-meltdown via PM to Roana. THIS IS NOT WHAT I NEEDED when I am trying to rebuild a basic amount of confidence in my ability to make glass art.

After a few minutes of panicked thinking, I had an idea. It's a round pattern, right? When I began cutting it with shears, the first thing I did was cut out the circle. Maaaybe I had just rotated it in relation to the reference (unsheared) pattern. After frantic comparison, I discover it's off 30°. "4" is actually "5', and so on. WHEEEW.

So, I had to recut a blue and a green piece, since rotating them offset them by one of each color. I knocked those pieces out. Then I realized I could have just rotated my reference pattern to match the cut up one. At least I was able to laugh...

With this second one, I plan to use etching acid either in the center of the star, and drybrush it out toward the tips, or at the tips and drybrush it toward the center. If I can make it match what's in my head, it will be beautiful.

[Edit later this week with completed pictures]

The first one, completed:

Archery Tournament Trophy (A Day of Archery, 2015)

I decided to try working on my painting skills. I grabbed a tiny brush meant for painting minis, and built a small wooden bridge to rest my hand. I got to work:

 It's hard to tell how the lines are doing while tracing, at least for me. Once I removed the original image I was very, VERY pleased with the line work. It has a somewhat irregular, rustic feel but I was ok with that.

Matting, to remove highlights

Matting cleaned up

I'm particularly pleased with this leg. The knee was a great accident.

After silver staining. I also wanted to stain the rock at the archer's feet, for some kind of vertical balance, but I tried three times and it blended "away" from the line too much. I moved on without it.

The finished and framed piece, at the archery field.

Pattern Shears

Going to try something new at my Laurel's suggestion to see if it makes me happier with my cutting accuracy. A lot of the super-precise artisans I've met online seem to use pattern shears, and she suggested it for me.

I hopped over to my local supplier and got a pair. The owner, an awesome woman, had me find them in a box under a cabinet because she hasn't had demand for them in years. The shears give a seriously big gap (and I triple checked they were foil, not lead not mosaic). For a few bucks I grabbed them anyway, but kept researching. I found shears that kept saying they removed 1/32" for foil. The pair I got locally can not be 1/32". I ordered a pair (made by Mika Intl, via Amazon, but this is not a plug). They DEFINITELY remove less pattern:

"Squeeze-bottle grip" foil scissors, left, Mika Intl shears, right.

I'm working on cutting up a pattern right now, planning on starting to cut it tonight. Lots of curves and difficult cuts, it should be a great test if this method works better for me than working "English" (glass on pattern on lightbox).

Estelle's Vigil: Scarab Platter

EDIT: I've had to do something stupid to get the text to appear on this post. Sorry!

Estelle has, as one of her personal badges, a scarab (dung beetle) pushing a ball of it's preferred element. It's a reference to her peerage theory, quoted here:

The Dung Beetle Theory of becoming a Peer:

First, you gotta find your shit.

Roll around in that shit a while, make sure it's the shit you want to bring home.

Then, you get your shit together.

You gather it up, make it nice and rounded, polish that shit up so that it shines.

Then, you gotta bring your shit home.

So you spend your time, rolling that shit along.  But because you're a dung beetle, you gotta roll it backwards, which means that you really have no clue where you're really headed... but eventually, after a long while, and with a little luck, you get that shit right where it needs to be.

And that's how you become a Peer.

The End.

She requested a scarab platter on which she can serve truffles during her vigil. She provided a design:

We went through available molds and glass colors to find something acceptable:

(There is an invisible piece of clear for the white in this picture. The glass looks slightly hazy -- to me it's as if someone spilled milk on it and wiped most of it off. It was sold as "cloud" and as a translucent white. It wasn't translucent as I would find out...)

I was a bit concerned about how to fire this one. Before I started this piece I had fired one half of the family badge plate (adjacent post). I think it's issues were closely tied to the irregular layering of the glass (2 layers in some places, 1 layer in others). I added more clear pieces to this blank (what I call the piece as it's being fused, before slumping) to try and keep more consistency.

The piece is not perfectly regular, which didn't surprise me. A little grinding fixed that up. There are some unfortunate lines between the body segments, and leg segments. I knew that would happen but I didn't want to overlap the pieces and potentially provoke bubbles. This picture shows how the white striked. I compared it to a piece of "opaque" fusible white, and the piece sold as opaque was actually more translucent than this cloud glass.

With these platters I progressively slid my firing schedule down from 1300 degrees. I think its near 1230 now, with no change in the hold times. I did that to try and avert "dog boning" especially in the square plates. This helpful advice came from the folks at Fused Glass Fanatics on Facebook.

These pictures show the completed (slumped) platter. The actual shape and depth is not conveyed well, I will try to take a better shot next week. The white is clearly NOT translucent. I used my grinder along the edges to make the shape a little more regular and remove some stabby-bits.

Estelle's vigil: Family Badge Platter

Estelle did not ask for this, but some time ago we discussed the idea of making a matched set of platters that, when joined, would form her family badged (used by her whole mundane household). I decided this was as good a time as any!

The plates feature blue bars on a clear (white) field, with green in the corners (skipping heraldry terminology for non-heralds). Because I use a base layer of clear, I didn't see the need to fill in the second layer with clear. This is the first time I've tried any fused project with clear. I expected that the blue might spread or contract a bit, but I thought it would be acceptable:

HUGE bubble. Right beneath the base layer, not between two. The edge was also very irregular. ALSO, the grey sharpie used to tag the glass didn't burn off as I had expected. So, scrapped it and started over.

This time, I added clear layers in the top. The results fused much more smoothly:

And the slumping went well. Initially the shape bothered me, I thought I was seeing the "dogboning" problem I've had in the past with this mold, and I had been correcting my slumping temperature down to try and adjust. After a couple of days I realized they are fine; the molds have a slight curve in a plane I didn't realize, and the shape is closer to the mold's shape than I thought.

The piece in the top of these pictures had some old kiln wash fuse to the glass. For the immediate purposes, this is fine, but I plan to remake it so it has the clarity of the second (bottom) tray.

Lessons Learned:

• Applied kiln wash apparently has a shelf-life!
• Better results with even layer coverage.