Optical Value and Impied Form in Two-toned Vector Graphics

I grew up on a farm where...lets just say if something was broken...you made do with what you had to make it work. It was amazing how many things one object could be used for if you were creative. A discarded wheel hub became a salt-lick holder. A used barrel of motor oil became a rain-shield for the combustion engines on the moveable irrigation lines. Last but not least, many broken aluminum sprinkler pipe became prime material for potato canons (although I don't recall ever firing potatoes).

I miss those days. I was just a kid. Life was so much simpler. One thing that I have taken with me, however, is that desire to creative problem solve.

Now that I design graphics, I am interested in addressing different sets of problems using the same creativity. One of the problems that we face in the west is sprinkler systems and water scale build up. This poses a problem for steeled stones with a laser etching on them. Laser etching is relatively new, so nobody really knows how long a photograph will remain on a stone, but at least for arid climates we are pretty sure of the damage that can be done. This is sort of a bummer because I have seen some incredible monuments with images being primarily laser etched. Just check out this link: http://www.paramountgranite.com/images/articles/jett_etch_grayscale.jpg  Laser etching does have the advantage of providing infinite gradations of value, which allows for photographic quality on granite.

I am in the development stages of developing graphics that, from a small distance, would have the illusion of value, not just two tones. The principle is the same as laser etching; optical mixing, only on a much larger scale. This technique is no secret to printers, especially woodblock and intaglio engravings.
Contoured lines have been used for centuries to imply value. For some reason I haven't really seen this on gravestones. I don't think its because its impossible, I just think that perhaps few people have really thought about the illusion of optical mixing on granite.

Well I did some tests:

 This is an image of a glass ball, with caustics(refracted light). This image has 5 shades of value, which were then turned into lines of respective varying diameter. The wider the diameter the darker the value appears from a distance.

I am very happy with the results. Though I have not had it sandblasted, I think that it would work very well. One of my primary concerns was for the plot-cutter. How can you put value into an image without having the cutter spending 10+ hours cutting the stencil. This would wear out your equiptment to fast, and would make pulling dots out a headache. With a contour pattern however, value is created with a relatively simple node path.

The question then comes to mind of what are the limitations of this technique. A line can only be so thin for a sandblaster to engrave deeply enough for it to matter. There is also the consideration of how close lines can be to each other before they get blown out of position and compromise the drawing. The last thing to consider is what is the threshold for the human eye when it comes to viewing an optically mixed image.

The ball and caustics are geometrical. But how would this technique measure up against something more organic, like, say a portrait of Abraham Lincoln?:

What do you think? I don't think the image is unsuccessful per se, but I think it is a tougher challenge to sell the human eye on something that has been geometrically stratified when the subject matter itself is organic. It really comes down to thresholds of value. An image like this might work: It is Linciln and at this point of his presidency, he looked pretty bad from all the stress of civil war casualty. But what about a little girl?

A computer cannot perceive planes, and therefore it cannot make contour lines that are appropriate for the respective plane they are contained in. This requires the discernment of a human. So I went back to square one and looked at...well not so much optical mixing, but implied form. Here is what I came up with:

Here there is some volume implied by contour lines in their respective plane Take Christ's hair for example, the lines, while following a natural path for hair to flow, creates the illusion of depth. This was done with a drawing tablet.


The image didn't quite feel complete. It would make a nice ink drawing to hang on your wall, but probably not a graphic to etch on stone. So then I tried to find a middle ground between hand drawing and the computer generated contour lines. I also took into consideration spacing for a gravestone...a format that would make it work in more of a radial pattern:

The original which I based this image from was a painting of Christ with a Child by Heinrich Hoffman. Hoffman was a 19th century realist most famous for his paintings depicting the life of Christ. I love his work...and knowing that his work is well known, thought that basing an image off of his work would make for a comforting graphic for someone who has lost a young child and would be comforted by the thought of the child happily in the presence of Christ. I am not sure if it works for me, however...The representation of Christ looks like the actor Liam Neeson.



This vector will likely be available in the free vector section of qualityheadstonegraphics.com.