Monday, September 29, 2014

Acanthus Leaf #2- How to: Forming the leaf shape

As I said in the last post, the acanthus leaf is a mix of natural and artificial; evocative of plants in its details, but grounded by a geometric regularity expressed through its form and construction. As with any artifice, it is helpful when a form is quickly comprehensible (what draws the eye in) and then detailed to the artists' abilities (what makes us keep looking.)

So how do you make an acanthus leaf? What follows is a basic primer in the form and features of the acanthus leaf. As with any primer, this is not the only way of doing it- in fact you will find very few examples that would follow this exact pattern- but it is a solid starting point that includes all of the basic features found in more complex examples, which we will look at later.

Here's my method, adapted from a 19th century book by James Page called, (appropriately,) Guide for Drawing the Acanthus, and Every Description of Ornamental Foliage (London, 1840).  This book was directed at tradespeople who wished to learn the methods for drawing ornamental foliage that looked good and would translate to three dimensional work, which is where the majority would be found, decorating architecture, furniture, and trade goods.

For your first attempt, I would recommend working on a standard sketch or drawing paper, at least a 9"x12" pad,  something that you can erase without tearing, and see through a little if you hold it up to the light. Architectural vellum (heavy weight tracing paper) also works very well. Use a medium pencil (HB) and have a good eraser on hand. Many of the steps are there only as guides, and will be erased later. You can use a ruler for some of the steps, but always draw lightly with it, as none of the ruled lines will show when you are done.

Step one: Let's start with a vertical rectangle that is 5 inches wide by 10 inches tall (about 12.5cm by 25 cm for our metric friends). Construct a grid that is 2 units by 5 units by dividing it in half horizontally and every two inches (or 5 cm) vertically. As you will see, many of these steps will only be temporary, so draw lightly. This one, in fact, will completely disappear by the end, and is only intended to show the proportions of the overall shape of the leaf.

Step Two: [Each new step will be drawn in red]. Divide the bottom edge into 3 equal sections and LIGHTLY draw the diagonal lines that connect the center of the top with the two divisions of the bottom, as seen in the illustration.

Step Three: Starting from the outside bottom corners, draw diagonal lines that are approximately parallel to the inner diagonals, stopping at the first division of the grid from the top.

Step Four: Connect the two diagonal lines you just drew to the top center point, as seen in the illustration. Check your curve against the one I have drawn here- you can use the straight diagonal I drew on the left side as a further guide to your curve. Notice how it forms a bow shape with the curve. Again, these lines are just guides for your overall shape and will disappear before you are finished, so draw them lightly, but try to make sure they are symmetrical (you can check this by folding your paper on the vertical center line to see if they overlap when you look at them through the folded paper.)

Step Five: OK, let's get rid of some of the lines now so it doesn't become too confusing. You can erase everything except the outline of the leaf and the two vertical diagonals that define the center rib of the leaf. It should look like this;

Step Six: Now we start the more artistic part of the process- less geometry and more eyeballing. We need to divide the central diagonals into intervals that get smaller as they get towards the top. I could try to give you some kind of formula for that (6, 5, 4.5, etc.) but it's really better to just look at the model below and give it your best shot. I've drawn the dotted lines so that you can better compare the intervals between the dots, but you can just draw the dots on your own sheet- that makes it easier to adjust as you go. Notice also how the very bottom interval is a bit smaller than the one just above it, but then they each get smaller as they go upwards.

Step Seven: The dots, or "eyelets" are a very important aspect of the acanthus leaf ornament. They give it rhythm and they also allow the eye to position the leaf in space. In a dimensional ornament (stone, plaster or wood) they are the registration marks that make reference points for the planes of the leaf that come later. They are derived from the natural shape of the divisions of the lobes on the leaf, but they also have a number of artificial aspects that I will show. 

If you look right in the center of the above photo you will see what the shape comes from. It is the place where one lobe ends and the next begins. It forms this little teardrop shape that is the basis for the artificial shape seen below. 

As you can see, the eye is formed by the overlap of each lower leaf over the next leaf, which is the convention when drawing acanthus for decorative purposes. It's not a bad idea to practice drawing the shape several times until you become familiar with it. It's formed like a "b" and a "d" in pairs, with the line of the lower leaf forming the part that continues upwards, covering some of the lobe above it. 

Once you've gotten comfortable with it, you can make the mark (just the eyelet- don't fill in the lobe yet) at each of the intersections that you made in step seven. These are the first marks you've made that will not be erased in the end! 

Next up: creating the lobes and the subdivision of the leaf edges. 

Thursday, September 25, 2014

Acanthus Lesson 1: A Proper Leaf, Part One (The Roots!)


This is the first lesson of several that I will post here on the origin, usage, and construction of acanthus leaf ornament in Western classical decoration. Ever since the classical Greeks, acanthus leaves, and their variant forms, have been used to enhance everything from temples to pickle forks. The form of the leaf has become so transformed by usage that most do not recognize the origin of its plant based shape, even if they are familiar with the plant, seen often in temperate climates as a garden specimen.
The leaf of the Acanthus Mollis plant, regularly used as a model for plant based ornament

Part One: Roots

When Louis Sullivan created his book on ornament*, he began with the organic, as conveyed by the shapes of leaves. He listed 14 basic shapes, somewhat less than the myriad collection in this illustration from Wikipedia, which pretty much covers the gamut of just about anything you could find on the planet, at least above the oceans. I also love being able to describe a leaf as a 'doubly serrated dichotomous flabellate"!

Leaf shaped ornaments have been covering man made objects for thousands of years, found on items from around the globe, and the shapes seen in the chart above are doubtlessly an early source of many decorative patterns, translated into other materials by busy hands. The illustration below shows a variety of capitals from Egypt, with ornaments derived from the leaves and blooms of palms, lotus, and papyrus plants. 

Plate 45 from Denon, Dominique Vivant - Voyage dans la basse et la haute Égypte, pendant les campagnes du général Bonaparte (1802)
The Greek sculptor Callimachus is apocryphally credited with inventing the Corinthian capital by Roman writer Vitruvius, as illustrated by this page of Claude Perrault's book on the Five Orders from 1683. According to Vitruvius, the sculptor came across a votive basket left at the tomb of a young girl, with a stone slab on top to protect the offerings inside. An acanthus plant had begun to grow under the basket, and thus became the basket form covered in leaves that we recognize today as the Corinthian order.

Perrault's illustration of the origin of the Corinthian capital, 1683

The earliest known example of a Corinthian capital is found at the Temple of Apollo Epicurius at Bassae (Greece), dated around 450 BC (incidentally , more than 100 years before Callimachus was even born), but it is thought to be a one-off, somewhat of an oddity in a temple that is mostly in the Doric and Ionic orders. A beautifully preserved early example was found in the tholos at Epidaurus, dated to the 4th century BC also.

Corinthian capital found at Epidaurus, Greece, 4th c. BC
As you can see above, the leaf shape used to ring the capital is a fully developed acanthus leaf, clearly derived from the plant itself, although regularized and codified in a way to make it something between a natural form and a geometric shape. That is where we will pick up in the next installment.

*Sullivan, Louis, A System of of Architectural Ornament According with a Philosophy of Man's Powers, New York 1924. Published posthumously by Frank Lloyd Wright.

Wednesday, September 10, 2014

Pic 'o the Day #1330- All in the details!

One of the rarely acknowledged benefits of the erosion of the monuments of ancient sites is the revelation of the sculptural substructures that support the ornamented surfaces. As the incredibly articulated and often quite delicate leaves, flowers, wings, etc. are worn away by the abrasions of time, we get to see what was hidden in the finished work: the work that went into sculpting the undercut parts.

A plaster cast of a large section of the entablature of the Temple of Vespasian, seen in the Tabularium, (part of the Capitoline Museums, beneath the Palazzo Senatorio), was the first piece that really drew my attention to this. The multiple moldings of this florid Corinthian ornament seem almost to be assembled from separate bits of stone rather than sculpted from a single massive block. The eggs of the egg and dart molding can be seen to be smoothly rounded as deeply as one can see, with no visible marks from the stone drills and chisels. This despite the fact that, apart from about thirty percent of the front face of the egg, the largest portion would have been hidden behind the surrounding molding. This not only makes that area invisible, it also makes it extremely difficult to carve and smooth. Yet there it is, clearly seen in the photo below. While this is a plaster cast piece in the museum, it is accurate to what is there, and the same type of carving can be seen elsewhere on similar original pieces.

Section of the entablature of the Temple of Vespasian in the Roman Forum, built in the first century AD. This temple was relatively small (for the forum), so there would only have been around 250 feet of this! It was also carved on its inner aspect.
The lower egg and leaf molding is equally stunning, with almost free standing leaves surrounding each egg, and tiny flowers and vines carved on the face of each one (Click on the photo for a closer view.) Incredible when you consider the overall number of these on the exterior of the temple, and that  (to my knowledge) they had no glue for fixing a broken bit, again quite incredible considering the delicacy of many of the parts. These obviously were carved in place, as it would have been quite impossible to get them into place without some damage to the ornament. 

With the overall amount of ornament on the building, there must have been hundreds of craftsmen who were capable of this technical work banging away up on the scaffold every day; the sound must have been deafening! While it is almost certain that a good portion of these sculptors would have been slaves, skilled work was often paid for, and in some cases, might have bought the slave's freedom. The flip side being that mistakes were most likely paid for in some not so pleasant ways. 

Detail of a Corinthian capital on the Temple of Mars Ultor, built by Caesar Augustus around 20 BC. You can see here the level of detail on the wings, which would have been virtually invisible at their height.

The top of the bell of a Corinthian capital and the point where the volutes attached, showing how the underside of the corona is carved flat and the bell curve continues around smoothly, despite the fact that these parts were largely hidden by the volutes themselves. From the museum at the Market of Trajan.

Rosette from the soffit of Temple of Mars Ultor. Each layer of the flowers is almost entirely distinct from the other. The egg and dart molding is similarly separated

Closeup of a molding with acanthus leaves showing how deeply carved the spaces behind  the leaves went, to the point that they were almost entirely freestanding. You can also see traces of where the rock drills were used to make the registration points of the leaves

An added benefit of a well crafted classical ornamental scheme is that even in its eroded state, it still presents a fascinating pattern of light and shadow, unlike modern ornament, which generally just looks dirty and dull after a few years of weathering.
The question must arise then of why would they expend so much effort on something that was largely invisible. Partly it IS visual, as can be seen by contrasting it to the modern reproduction moldings in the image below. While reproduction moldings might be well modeled and cast, the drama of the deep shadows in the Roman originals is lacking, making the copies look flatter (and this is actually some of the better pre-cast work available.)

Capital and entablature from a modern pre-cast company shows that the depth of shadows in the Roman originals is much more dramatic.

The Roman examples I have shown are from the early Imperial age (27 BC to 50 AD) corresponding to the 2nd and 3rd styles of painted decoration, which were the most painstaking and detailed, so partly it may have just been a cultural zeitgeist that briefly valued highly the attention to detail shown here, and had the resources in both the funds and the highly skilled artists available to make it happen. Other pieces from around the empire are certainly impressive, but rarely quite as detailed as what was found in the capitol city at this time.

There may also be some credence to the idea that because these ornaments were going on major new temples, that they had better be pleasing to both the clients and the gods they honored, with no shortcuts. It would be equivalent to the work done for St Peter's Basilica, or the Pyramids and monuments of Egypt, where they looked at the work as something sacred.

It will be interesting to see if new methods of creating moldings, such as the 3D printers that are increasingly being used industrially, will be used to create deeper versions of these patterns. It would seem to make sense, as this complex undercutting does not add time to the printing, and in fact it lessens the materials used, a benefit to both the cost of production and the weight of building. Artist Michael Hansmeyer has already created full size highly perforated columns using computer aided cutting, though his design module is uses mathematically generated modules rather than traditional structures. It will be up to a new generation that is familiar with computational modeling AND values the traditional design process to take the next step.

Thursday, September 4, 2014

Pic o' the Day #1329- Intermission

Still coping with a major computer meltdown that took out both my desktop Mac AND the peripheral drive that I had my pictures backed up on at the same time! Fortunately I have my pics spread around, so I'm not completely image free.

Here's one that caught my eye today, a detail of a Roman era fresco at the Museo Barracco, over near the Campo dei Fiori. It's a good lesson on how to paint greenery fast, a prerequisite for painting in fresco, where the plaster is constantly drying as one paints.

First off, notice how the overall shape is roughed in with a neutral brown color that relates closely to the background color, and also sets off the greens (which in Roman times were not very vibrant.) Secondly, see how the the bush is rendered as a sphere, with the light coming from the right side, so that the deepest shadow colors fall on the left side and the brightest colors are on the upper right side. Lastly, notice how the colors are separate and distinct from each other, and that even though they don't really fall the way they would on a realistic portrayal, they give a good impression of the tree that reads dimensionally and coloristically.