CREEP-ETCH
INTRODUCTION
While studying printmaking in London in 1970, I was introduced to
creep-etch. This etching technique creates gradual tonal change over an aquatint by
allowing the acid to gradually "creep" across the plate. This produces an effect that is
not possible when a plate is submerged in the acid all at once.
I used creep-etch from time to time to achieve tonal changes in the skies of
landscape images. Then in 1977, while working on a single plate image of a foggy
orchard, I realized I would need to use a whole series of creep-etches to accomplish the
desired range of tones. The technical challenges of this print, "Morning Fog", inspired
the development of my personal system of creep-etching. Over the years I have
developed methods to keep track of multiple creep-etches on single and multiple plate
aquatints. The following article details these methods.
CREEP-ETCH DIAGRAMS
Before I do a creep-etch I first draw a diagram of the plate and use it to
work out the etch times of the creep-etch. The diagram, often with a rough sketch of
the image, is drawn in pen. I use a pencil to draw in possible creep-etch times. I use
test plates and educated guesses to guide me in choosing the etch times. I often draw
and erase a few etch progressions before I settle on the times to be used.
When I have decided on the etch time progression, I draw a line beside an
edge of the diagram that represents the edge of the plate. On this line representing the
plate edge, I write numbers to indicate when the acid should cross that part of the
plate. These numbers are in the reverse order of the etch time numbers. For example,
the point to be etched the longest is where the creep-etch will start, and is marked with
a zero to indicate no time elapsed before the acid should arrive at that point. The area
to be etched the shortest time will get the highest elapsed time number of the
creep-etch since it indicates where the creep-etch ends.
Sometimes a plate will be removed from the acid and washed as soon as the
creeping procedure is completed, but in many cases the plate is submerged entirely for
a period of time after the creeping is finished. For example, a creep-etch of
ten-to-sixty minutes would be totally submerged after fifty minutes and would come
out in another ten minutes at sixty minutes.
The time at which the plate is to be removed from the acid is specified on
every diagram as the "OUT" time. The "OUT" time is the total elapsed time on the
stopwatch. If the plate comes out immediately after the creeping procedure, I write
"OUT" on the diagram beside the highest number in the creep-etch. If the plate is to
be submerged completely for a time after the creeping procedure, the "OUT" number
will be the time of the creep plus the time of total submersion.
Once the diagram is complete, the information needs to be applied to the
plate. I do that by sticking tabs or strips of masking tape on the back of the plate so
that they stick out from under the plate. On these tabs I write numbers that correspond
with the acid coverage times on the diagram.
As successive creep-etches are done over a plate, the cumulative etch times
may vary a great deal from point to point on the plate. I use the creep-etch diagrams
as records of the etches that have been done. To determine the cumulative etch time
of a particular spot on a plate, I add up all of the etch times over that spot as recorded
in the diagrams. That number, plus any other etching done over that spot, is a close
approximation of the actual time that spot has been etched in the acid.
In designing a new creep-etch progression, I often I add up cumulative
etch times for several spots on the plate and transfer them to a new diagram. These
cumulative times are also useful in making an educated guess of what tones have
been etched into the plate so far.
For some images I only want to do a single creep-etch and then even out the
etch times across the plate. To do this I do a "reverse creep-etch" which simply
progresses in the opposite direction of the first creep-etch and thus evens out the etch
times. Variations of this can be used to even out the etch times in darker areas after a
series of creep-etches have been used for lighter tones.
In some images I do multiple creep-etches between paint-outs. For example,
on the red plate for the print' "Crater Lake" I did five creep-etches from five
different directions before the first paint-out. Almost all of the etches on the three
plates for "Crater Lake" were creep-etches, and most were multiple creep-etches.
Creep-Etch Diagram for Red Plate of "Crater Lake"
DOING THE CREEP-ETCH
Since creep-etch requires that you spend extended periods very close to the
acid, it is particularly important that you wear proper lung and eye protection and that
the acid area have an effective fume removal system.
A basic creep-etch is just a matter of allowing the acid to gradually move
over an aquatinted plate. I used to lower the plate into the acid by hand, which does
work, but is hard to control and can get tiresome for longer etches. I now use a
gradual acid submersion method that is much easier to control.
I begin by propping up the acid tray, so that it slants at about ten degrees
from level. Next, I pour a small pool of acid into the low end of the tray, leaving
enough room so that the plate can be set in the tray and still be completely out of the
acid. It is important that the plate is dry. Acid will be pulled quickly into any damp
area. Now the stage is set for the creep-etch to start.
I set my watch to the stopwatch mode and place the plate in the tray. I push
the plate toward the acid until the acid is touching the zero point or line on the plate.
When a creep-etch starts at the edge of a plate, I carefully ease the plate into the acid
until the acid climbs the beveled edge of the plate and begins to move onto the plate.
At this point I start the stopwatch. The zero line for some creep-etches, however, is
located some distance in from the edge of the plate. In these cases, the plate is quickly
slipped into the acid until the acid arrives at the zero line. Then the stopwatch is
started and the creep-etch commences.
Example of Creep-Etch in Progress
The creep can be accomplished by either nudging the plate deeper into the
tray or adding more acid to the tray. I often use a combination, pouring the acid from
a glass measuring cup, and nudging the plate gradually farther into the tray with a
small piece of wood, such as the handle of a brush. Depending on the speed of the
creep I may have to nudge the plate frequently or may wait a minute or more between
nudges.
A creep-etch requires constant or near-constant movement of the acid over
the aquatint to achieve an even, unstreaked tone. This is particularly true for quicker
passages over fine-grained aquatints.
By using the slanted tray method it is possible to make the acid move at a
very slow but steady pace up the plate. With gradual pouring and/or incremental
pushing of the plate, the leading edge of the acid will be a small wall moving very
slowly up the plate. Sometimes the movement of the acid on the plate is so gradual
l that it can barely be seen, such as when it is only moving an inch every five minutes.
If the acid is too slow in reaching a specific area, it can be gently pushed
into that area with a feather or brush. If the movement is too rapid the plate can be
slightly pulled out and the acid carefully blown back. Clearly, you should be very
careful if you try to blow the acid, and you should wear eye protection at all times.
A major unwanted acid incursion may require a rapid removal and washing of the
plate. If this happens, try to remember to stop the stopwatch (but don't zero it). After
the plate is dry the creep can be resumed from the location where it was interrupted
and the stopwatch started running again.
To lessen the chances of streaks, a single creep-etch can be done as a few
shorter creep-etches. For example, a zero-to-sixty-minute creep could be done as three
separate zero-to-twenty-minute creep-etches, thus evening out the variations of the
creep-etches.
Sometimes I want to do a creep-etch that does not travel as a straight line
across the plate. Generally this requires that the tray be closer to level so that the acid
can be feathered into the desired areas. When the tray is close to level, any unevenness
in the plate is more likely to affect the progress of the creep-etch across the plate. For
this reason it is advisable to make sure that a plate is reasonably flat before planning
to do a creep-etch on it.
There may, however, be occasions when unevenness of a plate will be
intentionally created to alter the way the acid advances over the plate. For example, I
have set small pieces of wood under a plate to gently bend part of it up and thus alter
the progress of the creep-etch. This method is most effective for larger plates since
small plates don't bend sufficiently. The closer the plate is to level, the easier it is to
feather acid into nonlinear shapes on the plate. This creep-etch feathering technique
resembles a process called spit bite, which is another way of creating detailed tonal
variation. Spit biting is accomplished by gradually dripping acid onto a plate with an
eye dropper, paint brush, or other tool.
Close attention must be paid to the stopwatch to keep the acid moving across
the plate at the desired rate. After five minutes the acid should draw a line across the
plate between the two tabs with the five-minute marks. If you plan to use a feather to
move acid into certain areas it helps to have the diagram at hand to determine when
and where. Once a creep-etch is started you are pretty much stuck there until it is
done. I occasionally do ones that last up to two hours, and yes, it does get a bit boring!
PUTTING IT ALL TOGETHER
The key plate for the print "Loon Island Outlook" is a good example of
using creep-etch to create an image. Only four paint-outs were needed to create a full
range of tonal values.
Creep-Etch Diagrams for "Loon Island Outlook"
Before the first paint-out I did Etch Series #1. This was a combination of
two creep-etches, one from the top and one from the bottom, that met in the middle of
the plate.
I painted out the sky and the lighter parts of the water, then did Etch #2.
This creep-etch ended three-quarters of the way up the plate, after which the plate was
rapidly totally submerged in the acid. The arrow in the diagram is used to indicate the
essentially immediate passage of the acid over that area. After Etch Series #2, I painted
out the most distant islands and the rest of the water.
Etch #3 was specifically designed to give the central island a slight tonal
gradation laterally. This creep both begins and ends within the plate, as indicated by
the arrows. This etch was done by rapidly dipping the plate to the zero line, doing the
creep over 14 minutes, and then quickly submerging the whole plate and removing it
after six more minutes had elapsed. After completing Etch Series #3, I painted out
everything except for the darkest parts of the foreground.
Etch #4 was used as a "reverse creep-etch" to even out the etch times in the
darkest tones. The circled numbers are the cumulative etch times from the first three
diagrams, and were used to design a reverse creep-etch that would come close to
evening out the etch times.
This completed image was transferred to two other plates, and creep-etches
were used on these subsequent plates to create a rich variety of color and tonal change
in the completed three-color print.
I have found creep-etch to be very effective for landscape. It can also
provide useful effects for a broad range of imagery on single and multiple-plate
aquatints. The methods that I have detailed here are only the beginning of what can be
done using creep-etch over aquatinted plates. I encourage all interested printmakers to
experiment with creep-etch.
Stephen McMillan © 1994 (revised 2000)
