Monday, February 25, 2013

Buried Treasure

This is another obsessive project where I spend an unreasonable amount of effort trying to capture a particular look for a prop. In this case, I wanted to duplicate the appearance of a fired clay idol that had been buried underground for a long time.

I'm certainly not the first person who's tried to duplicate the patina of an excavated artifact.  In fact, reproducing the combination of dirt and soluble salts that accumulates on those items has been a favorite of forgers for centuries.  Get the patina right and you can turn a 2 piastre clay figure from the souvenir stands of Cairo into a genuine archaeological find worth considerably more to a gullible tourist.

Unfortunately, I couldn't use the traditional approach of placing the "artifact" in the water tank of a toilet and waiting for the whitish haze of lime and salts to develop naturally.  That process takes months, although the results will pass even close inspection.  Worse, my material of choice was cold porcelain clay.  When dry it does an excellent job of duplicating the mass and hardness of real clay, but it's considerably easier to work with.  It's also water soluble, which means exposing it to water once it's dry will just turn it back into a malleable lump of PVA and cornstarch again.

That meant the patina had to be a combination of surface texture and a convincing paintjob.  Sculpting the actual idol went relatively quickly.  I wanted something primitive, but not too crude.  There had to be a certain refinement to the lines of the piece.  I eventually settled on a shape that looked like a ball on top of a curved cone.  I wanted to have as few features as possible so that it could pass as an odd skull fetish or maybe a decorated hand tool.  At the same time there had to be enough detail that someone familiar with the Mythos would recognize it as far more than a glorified hammerstone or pestle.

Here's the final result. I'm skipping the entire sculpting process, mostly because it looked terrible right up until I applied the final paint job. It probably didn't help that I tinted the clay a dark reddish-brown, so it looked uncomfortably like a lump of...well, something unpleasant.

A view from the right. Building up the texture of the encrustations was a two step process. On the first pass I stippled the entire surface with paper clay thinned down to the consistency of heavy cream. The second application was a spot application using a thick, intentionally lumpy mixture. The entire piece is about six inches long.

This shot gives a better look at the contrast between the terracotta base surface and the patina treatment. I wanted the reddish brown "clay" of the idol to peek through the accumulated salts and lime.

The patina buildup is heaviest on the face area of the figure, but the eye sockets only have a light layer of calcium haze.  That seemed to make sense if the idol had been dropped and then buried.  The weight of the head would have positioned the idol face down and tilted at an angle, leading to more buildup on the lower surface.

Click through on this shot to get a good look at how the final paint treatment came out. The base coat was a thin layer of terracotta over the existing red/brown surface of the idol. On top of that I did a wash of thinned white paint to produce the hazing effect, followed by drybrushing with burnt umber, light tan, and a touch of white.

All in all things turned out pretty well.  The result looks convincing, but the patina buildup may be a bit heavy.  I should knock it back with a light wash of terracotta. What I found interesting is that this style of patina is applied exactly the opposite way of a normal finish.   Normally you start with a dark basecoat and apply increasingly lighter highlight layers.  In this case the dusty appearance comes from starting with a midtone base and then a pure white wash, followed by a darker layer of burnt umber and a light drybrushing. 


Ari said...

It's wonderful! Not only the sculpture but the research you did to give the prop a realistic look. I love the idea of the drop and bury. Would love to have one if you ever sell.

Propnomicon said...

@ Ari

Thank you for the kind words.

Oneiros said...

Very nice.

I don't know from where, I seem to remember reading that you can age stone effects by painting the surface with live yogurt and leaving it in the sun for a few days.

Raven said...

It's beautiful work, creative problem solving,... and a pity that the original material (cold porcelain clay) left you with such problems to solve. Have you ever worked with stucco? (See the article for illos.)

Historical authenticity in spades; starts wet, so you can mold it or work it to your heart's content; dries hard and dense for long durability ("architectural decoration"); takes color easily.

"Traditional stucco is made of lime, sand, and water. Modern stucco is made of Portland cement, sand, and water." — makes PVA and cornstarch seem just a bit weak by comparison, yes?

There's a roadside restaurant near us, goes through owners every year or two because frankly the traffic doesn't bring many potential customers past (location too rural), despite some wonderful steakhouse and Italian cuisine incarnations. The Italian format has lasted years, though, through multiple owners, because no-one has wanted to change the wonderful wall art one past owner put up with stucco and paint: a convincing re-creation of ancient Roman murals ("cracked walls" and all) surrounding diners with reminders of the joys of good dining in times long ago, depicting amphorae of wine, vinyard scenes, and feasts with bunches of grapes held above the mouth; oh, and they even served appetizers wrapped in grape leaves.

Stucco. It's a good word. Hmmm. Stucco-Cthulhu? Imagine that for, say, a mural work.
Recaptcha codeword: Statiua. How eery.

Propnomicon said...

@ Oneiros

The Significant Other did exactly that on some super-tufa planters she made. After a few weeks the concrete looked like it had been sitting in the garden for a century.

@ Raven

The only lime based materials I've fiddled with are plaster and water putty. In both cases they were used for casting, at which they excelled.

The reason I love cold porcelain so much is that I can manipulate it's malleability so easily. Depending on the proportion of solids added it can be adjusted from the density of cold oil-based clay down to something only slightly thicker than water. And it doesn't hurt that it's so cheap to experiment with.

Raven said...

Yes, well, you saw the ingredients list for stucco. How expensive is sand? The Portland cement and water you want to keep to the quantities needed to set (crystallize) eventually, and hold all the sand in place when they do, but that gives you some range in setting-time and sand-to-cement ratio. I'm sure as a homeowner you've laid enough household cement to be familiar with the process. This is just aiming for artisan-grade uses, but let's see if we can avoid paying artisan-grade prices for the materials.

Also, there are several reasons an idol head might have wound up buried, and only two of them are accident or enemies. Back in 2001 I discussed on Usenet the charming custom, shared by pagans and Christians, of burying one's own venerated divine or saintly figures, head downward, when they haven't been delivering on one's prayers... at least until they do deliver, in which case they get dug up... or else some other god or saint will become the new beneficiary of worship. Yeah, extortion by strike!

(And why shouldn't loyalty be conditional? It's supposed to be a two-way street!)

Or, as Guenevere sang in Camelot:
     You know how faithful and devout I am.
     You must admit I've always been a lamb.
     But Genevieve, St. Genevieve,
     I won't obey you any more!
     You've gone a bit too far.
     I won't be bid and bargain'd for
     Like beads at a bazaar.
     St. Genevieve, I've run away,
     Eluded them and fled;
     And from now on I intend to pray
     To someone else instead.

David Grubbs said...

Do you have a favorite cold porcelain recipe? I've found several versions online and am curious what you use. (Unless, of course, you have a top-secret proprietary mix!)

Propnomicon said...

@ Raven

You continually amaze me with your breadth of knowledge, and I mean that in the very nicest way.

@ David Grubbs

I use the basic 2 cups each of PVA and cornstarch mixture most of the craft sites have posted. The only changes I've made are adding a teaspoon of glycerin, a teaspoon of vinegar, and about half a cup of boiled linseed oil.

David Grubbs said...

Thanks! It looks like a user-friendly, wallet-friendly medium!

Raven said...

6"You continually amaze me with your breadth of knowledge...."

Oh, I'm the black sheep of my family, believe me. My aunts alone — growing up among strong brilliant women like that, one just doesn't have a chance to start developing delusions of grandeur [let alone female inferiority]. My mother the pioneering maize geneticist always felt the baby of the family next to her sisters — the oldest being the first woman ever to get an engineering degree from MIT and the founder of MIT's Language Lab; the second being the translator of Trotsky's Diary and the "salon hostess" or "den mother" of Harvard literati (her 9-year-old daughter, my cousin Marina, provided the model of "American girl" speech Vladimir Nabokov used to write Lolita); the third, etc.

"Breadth"... one of my parents' friends and colleagues at University of Missouri (which is where they worked when I was born) was an associate professor in Botany, the gifted and intense Alexander Fabergé (grandson of the jeweler Carl). He was working feverishly on anthocyanins, which like chlorophyll give plants color (though red, purple, or blue rather than green), and at parties literally found it hard to discuss any other subject. ... In our own family conversations for the rest of her life, my mother would signal any change of subject by imitating Fabergé's usual impatient interjection, "Speaking of anthocyanins!" (which no-one had been). ... I took this as a warning not to be the sort of person who could only discuss one thing at parties.

So now, may I show you my Necronomicon? discuss H.P. Lovecraft? tell you all about Cthulhu and R'lyeh? warn you how to recognize a Deep One? ... Or... would you rather discuss The Yellow King by Robert Chambers instead? ... Hey, there's plenty of room on the couch, you don't have to go....

Stefan said...

I like it alot. It greatly reminds me of the fossils I collected as a child on the shores of the Baltic Sea.