00100				PHOTO ETCHING INSTRUCTIONS
00200				Edith Smith, Instructor
00300	
00400	I. Cut photo-plate to size desired.  Re-tape remainder and projected plate.
00500	
00600	II. Film Preparation:
00700	
00800		Film is prepared for exposure onto Revere photo-sensitive zinc plate.
00900	Kodalith 3 film may be shot in the darkroom.  For intaglio processes, a film
01000	POSITIVE is made, always using a half-tone screen.  A 133 dot screen is preferred.
01100	Test strips should be shot through strategic lights, half-tones and darks at
01200	exposures from 45 to 75 seconds.  Not only do you want the exposure that does
01300	most for your particular image, but you want one that will carry a clear dot
01400	pattern in the blacks.  This is one of the most important considerations in
01500	photo intaglio work.  After longest test exposure, a 20 to 25 second "flash"
01600	is recommended -- with negative removed from carrier and enlarger raised all
01700	the way up.  This is to insure a dot pattern in blacks (to hold ink in the
01800	darkest areas).  Check you test strip results with a magnifying glass.  When
01900	you've decided on correct exposure time and flash time, shoot your plate-sized
02000	Kodalith positive(s).  For relief printing on zinc, a Kodalith negative is used,
02100	and no half-tone screen is necessary.  For grainy silk-screen-like prints, you
02200	should use this method.  I prefer a 1 part H2O, 1 part A and 1 part B developer
02300	to the usual stronger mixture.  Thus, your image will come up slower and you
02400	have more control.
02500	
02600		After you finish with your darkroom work, you will probably want to
02700	modify your Kodalith through any one of many creative techniques.  You may
02800	wish to cut the film(s) up into a collage or overlay (double image).  You may
02900	wish to scrape away large or small sections with a knife or etching needle.
03000	You may wish to add blacks with brush or pen and ink (non-crawl acetate ink
03100	or India ink) -- or with litho crayons or pencils.  You may wish to turn certain
03200	areas into cloud-like, vaporous half-tones by applying a 50% clorox, 50% H2O
03300	solution with cotton.  Precise white lines are created in your intaglio print
03400	by scratching white lines out of inked or exposed film areas.
03500	
03600		If you are drawing directly on film, without using a photographic
03700	negative, utilize .005 or .007 acetate.  This may be collaged or overlaid
03800	also.  But remember to test overlays carefully for longer exposure.  Any
03900	drawing techniques just discussed may be used on acetate, plus any you think
04000	just MIGHT work.  Film, either singly or in collage or overlay must be the
04100	same size as your intended photo plate in total dimension.  Remember, the
04200	image you see UP, as you lay the film on top of your plate for exposure, will
04300	be MIRRORED in your final print.  Hence all writing, lettering, etc. should
04400	be BACKWARDS (emulsion side down) during exposure.
04500	
04600		Before exposure, pour Revere Developer into a metal or glass tray.
04700		Don't use rubber or composition tray.  Use well-ventilated area.
04800	
04900	III. Plate Exposure:
05000	
05100		Make sure glass you place over your film and plate is cleaned with
05200	ammonia and is free of scratches over image.  Set lamp 18" above glass.
05300	Cover glass with plywood for one minute as lamp heats up (this is to give
05400	full play to ultra-violet).  Then try a series of test exposures across
05500	strategic parts of your film.  No effect is possible at under 3 minutes.
05600	Beginning exposure over-all is 3 1/2 minutes.  Moving board or cardboard 
05700	over plate, gradually close down the exposed area every 30 seconds, till
05800	the last strip of the test strip has received about 7 1/2 or 8 minutes
05900	exposure.  Most work needs a plate exposure of about 4 1/2 - 5 1/2 minutes.
06000	For all-drawn work, or for Kodalith WITHOUT half-tone screen, about 5
06100	minutes is recommended.
06200	
06300	
06400	IV. Plate Development and Wash-Out:
06500	
06600		Procedure for test strips and real plate is exactly the same.  With-
06700	out touching top of plate, carry plate to developer.  Submerge photo-plate
06800	with the same motion you use to enter film into a developer.  Exposure
06900	time is 2 1/2 minutes (unless developer is very old.)  Agitate gently but
07000	continuously.  The care with which you handle the plate when lifting it
07100	from the developer and until it is completely "set" after several minutes 
07200	of water wash-out is crucial.  This is the crucial time of the whole
07300	process because at this time the resist is soft and jelly-like.  Don't
07400	touch top!  Let plate drip in sink for one full minute.  Then, with a
07500	VERY SOFT stream of COLD H2O, begin wash-out, keeping plate tilted at
07600	a sever angle to the stream.  After about 2 minutes you can increase the 
07700	amount of water in stream.  Wash-out should last 4 minutes.
07800	
07900		Set plate up leaning against a wall on top of a clean counter
08000	or table for 1/2 hour.  Funnel your developer into re-cycling drum
08100	immediately.  Have another student hold funnel.  Clean hands thoroughly.
08200	
08300	V. Hand Work and Acid Baths:
08400		1. Intaglio plates with half-tone screen should probably be bitten
08500	10 to 12 minutes, depending on acid strength.  Open bite.  Then if there
08600	are some black areas that haven't received a dot pattern, the "tooth" to
08700	hold the ink in these spots must be supplied by aquatint (or drypoint, if
08800	problem area is small).  Although rosin aquatint MAY be used, plastic spray
08900	is preferred.  Bite plate 4-8 minutes more, depending on bath strength
09000	(5 minutes average).
09100	
09200		2. Plates that are to be bitten for rolled relief printing should
09300	probably be bitten down at least an hour.  Color viscosity biting can also
09400	be tackled at this point, if desired.  However, any section of plate defined
09500	by a screen should probably not be bitten longer than an hour; undercutting
09600	could destroy the pattern.
09700	
09800		3.  ANY kind of plate modification or etching or drypoint technique
09900	may be utilized either before first bath or at any later stage.  Drypoint
10000	through the blue photo resist is beautiful.  Needled, etched lines may be
10100	added at any time.  The resist may be removed wholly or in part with acetone.
10200	A vaporous effect, unequalled in any other phase of etching, is achieved by
10300	dragging an acetone-soaked rag over plate and eliminating resist selectively.
10400	Any length of bath follows, depending on effect desired.  Liquid ground can 
10500	form new resist patterns once photo-resist is removed.  New aquatinted shapes
10600	can be created in counterpoint with the original photo half-tone if resist is
10700	partly or wholly removed.  Taped hard-edges can be created over photo-image
10800	before or after initial bath.  Whole new areas can be scraped or bitten: these
10900	practices are particularly applicable if several photo-plates are to be used
11000	in registration; the concept of "dropping out colors" applies.