Erasers and Erasing
July 20, 2011
It's been awhile since I've posted, so I thought I'd share some discoveries I've made in the area of erasing. The particular subject I would like to address is the method I discovered awhile ago for erasing lines cleanly from paper, but first I'll give a rundown of several eraser types that I find useful.
These firm, white erasers are available under a myriad of brand names, and even uncommon brands seem to perform quite well. I use this kind of eraser in two forms: regular "block" erasers, and "stick erasers, which are often retractable, like Pentel's "Clic Eraser", or refills for electric models. The obvious advantage of being able to get into tight areas of a painting is augmented by the fact of the erasers length; i.e. it will stay the same diameter until it's all used up. You can only use the corner of a large eraser until it wears away, which it will do in short order, however I will still occasionally cut a sliver off of a large vinyl eraser to create a sharp edge, which will last long enough to make a few white lines in charcoal or graphite. Vinyl erasers are ideally suited to this, and they can also be cut to a variety of custom sizes and shapes. The pretty gentle on paper so they make a good "all purpose" eraser. This is especially true of the higher-quality ones like General's "Factis" extra-soft eraser. The more firm varieties (under many trade names) are good for stubborn lines.
It has been my observation that the "regular" rubber erasers, which are often manufactured in shades of pink or green, tend to harden after awhile. Those who like to use them a lot probably won't be inconvenienced by this, as the frequent use of them will wear the eraser down before oxidation sets in. If an eraser is allowed to "dry out", it won't be much good thereafter, because it will be hard on the support, and leave streaks of pink or green in its wake whether you're erasing on paper or boards. For this reason, I always keep a vinyl eraser in the garage for woodworking etc.; a rubber one is just too susceptible to the summer's heat. Apart from this factor, these make fine "workhorse" erasers, especially on a tough support like Wallis sanded paper, where even an oxidized one may come in handy.
Gum erasers and non-abrasive cleaning pads seem to be quite similar in principle. The gum erasers work well for erasing large areas, but but are a bit messier (and possibly harder the support) than vinyl ones. The non-abrasive pads seem to be stuffed with particles of the same gum-rubber, and will also cover large areas quickly, with a similar amount of rubber crumbs to brush off. Just a matter of whether it's worth the mess in a given situation.
When it comes to taking out tiny areas in a pastel painting on Wallis sanded paper, nothing beats an old fashioned typewriter eraser. It's true that the abrasive in this type of eraser would be too rough on standard paper, but the Wallis is primed with a seriously hard grit, aluminum oxide or something similar, and seems to take this sort of treatment well. The advantage this eraser has when it comes to sanded paper, is that the fine erasure particles fall off (or can be blown off) readily, whereas regular vinyl or rubber erasure tends to get trapped in the grit and combine with pastel dust to form a film. (I don't know whether the typewriter eraser would eventually wear the grit off the paper, because I try not to overdo it.)
Abrasive ink erasers are also to rough for ordinary paper in most situations. It might be O.K. for the sanded paper, or on an area of paper that will not be reworked. In these areas that will not need to be redrawn, I've found fine-grit sandpaper will work, at least on tough vellum bristol, (as for a final cleanup of smudges in the margins of the paper.)
If kneaded erasers are important for pencil, they are practically essential for pastel. As I noted above, conventional erasers tend to gum up the pastel, but this effect can be minimized by:
1. Brushing away the loose pastel with a stiff paintbrush and/or...
2.Lifting out surface pastel from the area to be erased. This may then be followed by a conventional eraser with less likelihood of ending up with a clogged eraser or smudged paper.
This brings us to the main point I want to make. After years spent trying in vain to reduce the amount of staining and "ghost lines" left by erasing, I finally found a way to erase much more cleanly with hardly any ill effect on the paper. What I learned was that it isn't so much the drawing implements that make indelible marks...the problem is more one of erasers making indelible marks!
Allow me to explain.
When you make marks with a colored pencil for example, (with moderately firm pressure), what is happening? The "macro" photo below shows a sample of colored pencil on bristol board. It seems to me that colored pencil marks are basically clumps of waxy pigment, most of which sit more or less on the surface of the paper. Most of the pigment isn't embedded in the paper at all. Half of the swatch has been worked over with a vinyl eraser.
Hmmm... a lot of staining here. Here is what I believe is happening:
The eraser hits those intact little particles of waxy pigment, and rubs them to powder. As I continue rubbing, I am not only working this powder into the paper, I am actually smudging it around, and If I was drawing with a soft lead, there's a good chance I will never get it all out.
Now for the improved method.
I use a kneaded eraser (or substitute; more on that in a moment) to pick up as much surface pigment as possible. This involves some persistence, pressing down firmly on the eraser, giving it a slight twist for good contact, lifting up, and repeating. I also keep trying to use a dfferent area of the eraser for each stoke, by rotating or kneading it before pressing it down again. I try to remove a good 50 to 75% of the saturation, until the marks look something like this:
Next, I erase whatever is left with a conventional vinyl eraser. As you can see, the resulting stain is much less noticeable than the one in the top image, where I tried using a conventional eraser alone.
For this demonstration, I used a Raspberry Prismacolor on a sheet of Canson vellum-bristol, but the principle can be expanded ,(and I have certainly done so), to include other media, like graphite and charcoal, and alternatives to commercially made erasers. (Results will vary depending upon the specific media used. ) As far as alternative erasers, the possibilities are endless. What you want is a material with enough adhesion to capture the superficial pigment, without being aggressive enough to damage the support. Here are various items I use:
3M Wall Putty. Good substitute for kneaded eraser. More aggressive; good for use with pastel.
Mortite putty-caulk. Too sticky on it's own, but it adds tactility to a worn-out KE.
Masking tape. Not for every surface, but some brands are great for pulling large areas of pastel off of Wallis sanded paper or Pastelmat, especially if you build heavy layers. Cuts down on mess considerably. Test on a scrap to determine suitability for a given application.