SNAG-ging a Representation

A few of my students organized a Holiday-themed Alla Prima afternoon this past week. For some of our newer artists that seemed a tad more apprehensive about jumping into the challenge—I offered a short acronym for them to keep in mind when trying to capture a likeness their observed subject.

I told them ya gotta SNAG it. ( I know, I know, it’s super cheesy but it works .) Here is the breakdown of what the acronym represents:

S- The Visual Survey. This step consists of the most basic measurements/dimensions of a subject or composition. It often includes, at a minimum, the greatest height and width of the representation, along with a center line. This state may also include envelopes if you like.

N- The Notan. This is the basic map of the light and dark overall light and dark areas of your subject. Imagine that every value you see must go into one of two categories (light or dark). This categorization builds a notan map. Static squinting is very helpful here (a squint that is severe enough to abstract a percept into (mostly) two general values.) We try to limit this map to only two values (one being the surface ground and the other a light application of a material that would be as “non-disruptive” to subsequent applications.) Additionally, some may also choose to leave the notan stage as a delineated map without any value lay-in. This option is just fine and is what we often refer to as a cartoon.

A- Anchors . An anchor describes a concrete landmark on our map. These marks are often your darkest darks, lightest lights, or highest chroma colors, etc. These marks are the “givens,” relative to your available materials ( some might say a form of “palette calibration,”) that you will use to solve for all other values/colors.

G- Gradations . This is the stage where value/colors are added outward from the anchors (based on their relationships to them.) These gradations/evolutions “growing out” from the anchors are built out like bacteria spreading out from several anchor points in a Petri dish. Dynamic squinting comes into play here to test/confirm perceived value/color relationships between the subject and the representation (as opposed to static squinting which is used to suss out the basic light/dark pattern.) An example of dynamic squinting would be as follows: Let’s say you place a value/color next to an anchor based on observations of your subject, but would like to be more confident about it. Well, one way to test it would be to look at the region of your SUBJECT in question while you slowly increase the severity of a squint until the two specific target values/colors are perceptually “fused.” The squint is then held at the exact severity where fusion occurred while one’s gaze is shifted to the corresponding values/color within the REPRESENTATION. If the values on the representation are not perceptually fused, you can be relatively certain that one of the values/colors is “incorrect” (and it’s usually not the anchor—hence why early anchors are so important.)

Hope that this simplification is useful to all of you as well!

and Happy Holidays to you all~~~


I love it! Are you drawing your “SN” directly on the canvas with graphite?


Thanks Jacob–GREAT question. My S and N (if N is left as a cartoon without value) are done in graphite (directly onto the canvas/panel) for my more finished work. However, for my “looser studies” and alla primas—it is all done with paint.


@AWaichulis I already commented over on Instagram, but I’ll reiterate how great this is! It’s helpful for me personally on a couple different levels.

BTW, what’s your take on graphite underneath oil paint? Of course I’ve heard it “strikes through”, but that’s always been anecdotal. I’ve never heard a really informed explanation of how it interacts with oil (or not).

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Happy Holidays Tim! As always, I am thrilled to know that this was helpful!!!

As to your question–I passed along the inquiry to materials guru George O’Hanlon and his group. I too have heard many repeat the claim—but I have never read an actual paper on it–nor have I found anyone yet that can point me to a reliable source for confirmation. I’ll update this post if/when I do.

In any case–I have used graphite for my cartoons for twenty years now. They were more elaborate in the beginning but have since tapered off to more general “visual surveys.” Even so, I have only ever had one problem with adhesion which was due to a larger-then-intended graphite chunk that that was somehow lodged in the surface (it was small and I just missed it when painting). Even though it was a quick fix it still got me in the habit of lightly sanding my cartoon to ensure that there is no excessive graphite anywhere on the surface. The entire cartoon is quite ghosted when I begin to apply paint so any potential migration is not a concern of mine whatsoever.

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Ok Tim—it turns out (as I suspected) that the “graphite migration” claim is a myth. This is from MITRA (The Materials Information and Technical Resources for Artists-University of Delaware):

Regarding the idea that graphite can migrate through the paint layers…

This has become a common misconception amongst artists that can be easily explained. Most paints containing fatty acids (oils, alkyds, and egg tempera) can become more transparent as they age. The predominant effect is caused by the conversion of higher refractive index pigments (such as lead white, zinc white, etc.) into soaps, stearates, and other complexes that have a lower refractive index, and therefore create a more transparent paint layer that eventually exposes the underlying paint layers or underdrawing. In oil paintings, this is further compounded by a slight increase in refractive index that occurs in oil binders over time. This given the optical impression that an underdrawing (done in graphite, for example) is “migrating” to the surface when in fact it is simply a natural chemical change that has occurred in the overlying paint layers. This phenomenon is also associated with the term “pentimenti,” as the increased transparency of the uppermost paint layers can reveal earlier compositional changes and even unrelated paintings or sketches.


This brilliant! Good to know what’s actually happening. I’d heard something along these lines, but nothing definitive.

The idea of sanding the graphite cartoon is also really helpful. I’ve taken to using watered-down india ink in a pen, but I lose the ability to correct. I’ll have to try graphite followed by sanding on my next piece.

Thanks again!! :slight_smile:


In the spirit of Christmas yet to come, I snagged your reference, and did an alla prima too. Didn’t come out too badly. The notan and anchors are super useful for control and keeping things from getting too wild and enthusiastic which I tend toward giving a more consistent result. Cheers!


Nice!!! Merry Christmas Martin~~~Here’s to another year spent in the pursuit of great masterpieces!


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