古典印相工艺蓝晒

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2018年，Mike Ware发明，单液配方，包括：高、中、低反差3种药水，单液配方使用非常方便，3个不同反差的药水可以获得不同反差效果，如需精确调整反差可将高低反差药水按不同比例混合。

新配方不采用棕色柠檬酸铁铵，草酸高铁铵等药。可以调整氨水浓度改变反差。
Introducing Three Varieties of Cyanotype
The ‘Classic’ method of cyanotype invented by Sir John Herschel in
1842 has been practised essentially unchanged ever since. Of all
alternative photographic printing processes, it is the oldest, safest,
and cheapest - but not the best in image quality. The drawbacks of
the ‘Classic’ formula are due to wide variability in the composition of
the sensitizer chemical, ferric ammonium citrate, aka ammonium
iron(III) citrate: it may be poorly absorbed by paper, losing image
substance during wet-processing, which causes a limited exposure
scale with poor tonal gradation. These problems were overcome in
1995 by my chemically up-dated version, named ‘New Cyanotype’,
which employs pure ammonium ferric oxalate to provide a convenient
single-bottle sensitizer, having a shelf-life of years with dichromate as
a preservative. The ‘New’ formula only requires a much shorter UV
exposure (~1/8th) and yields a Prussian blue image with a long,
smooth tonal scale of excellent colour, having a maximum density
verging on black (1.7). The wet-processing is ** and offers some
control of contrast. For further information consult Cyanomicon II at:
https://www.mikeware.co.uk/mikeware/downloads.html
Preparation of the ‘New’ formula does demand some manipulative
chemical experience. That is not required for this latest version, called
‘** Cyanotype’, which avoids commercial ferric ammonium citrate
altogether but effectively makes it in situ, easily and cheaply, from
widely-available pure chemicals. Unlike ‘New’, the ‘**’ sensitizer
contains no toxic dichromates or oxalates, making it safer for children
and the environment. The ‘one-bottle’ sensitizer is faster than an
average ‘Classic’ two-bottle formula, but still slower than ‘New’. It has
excellent tonal separation with a high Dmax of ~1.5 and it can provide
an exposure scale varying from 2.7 to 1.8 depending on the sensitizer
formula, so the contrast can be fine-tuned to match widely differing
negatives - an innovation which has not hitherto been possible with
cyanotype.

烟灰缸

谢谢分享

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Chemicals needed for Preparing and
Processing ** Cyanotype Sensitizers
Purity: **ytical Reagent grade 99%+ is preferred, where possible.
Use only fine chemicals from reputable suppliers.
Substance & Formula
Quantity for 100 cc
Sufficient to coat ~60 10x8 in. prints
Citric acid monohydrate C(OH)COOH.(CH2COOH)2.H2O
13 g
aka 2-hydroxypropane-1,2,3-tricarboxylic acid
OR Citric acid anhydrous C(OH)COOH.(CH2COOH)2
12 g
Iron(III) nitrate nonahydrate Fe(NO3)3.9H2O
12 g
aka ferric nitrate nonahydrate
Ammonia solution NH3 (supplied in various concentrations)
aka ammonium hydroxide NH4OH
10% w/w (S.G. 0.959)
~50 cc
Warning: commercial brands of ‘household ammonia’
may contain additives that spoil the chemistry
OR use one of the more concentrated laboratory reagents:
24% w/w (S.G. 0.912) 25% w/w (S.G. 0.909)
28% w/w (S.G. 0.900) 30% w/w (S.G. 0.894)
32% w/w (S.G. 0.890) 35% w/w (S.G. 0.880)
~20 cc
Concentration may easily be checked with a hydrometer
Potassium ferricyanide K3Fe(CN)6 99% purity is important
10 g
aka potassium hexacyanoferrate(III)
Water, purified, H2O
100 cc
(distilled, de-ionised, pharmaceutical, etc.) to make
Tween 20™ C58H114O26
~1 cc
aka polyoxyethylene sorbitan monolaurate; polysorbate
Abbreviations:
g = grams
cc = cubic centimeters = millilitres
S.G. = Specific Gravity in g/cc at 20ºC
% w/w = Weight percent Weight in g/100g
Processing Solution:
Quantity for ~60 10x8 in. prints
Citric acid (as above – either variety)
200 g
To make ~1% w/v solution dissolve 10 g in 1 litre of water
Use to process 2 or 3 prints only

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Safety
PROTECT YOUR EYES with safety goggles.
Avoid inhaling ammonia vapour!
Gloves are advisable.
Apparatus for Preparing the Sensitizers
Scales or balance sensitive to 0.1 g
Glass beaker 200+ cc
Measuring cylinder (US: “graduate”) 100 cc
Glass stirring rod or magnetic stirrer and ‘follower’ bar
Brown glass bottle 100 cc
Filter funnel and filter paper
Tungsten or LED lighting to work under, not fluorescent or daylight.
Illustrative of typical equipment – not all required hereAlternative Photographic Processes: ** Cyanotype ©Mike Ware 2019
Preparation of ‘One-bottle’ Sensitizers 1
Purity: If high photochemical precision is an issue, use **ytical
Reagent (AR) grade chemicals, purity 99%+, and weigh to ±0.1 g.
N.B. All the following instructions must be carried out under dim
tungsten or LED lighting, not fluorescent tubes or daylight.
1. Low Contrast: Exposure Scale ~2.7
1) Weigh out 13 g of citric acid monohydrate into a 200+ cc beaker.
OR 12 g of citric acid anhydrous.
Add 35 cc of pure water, and stir to dissolve all the solid.
2) Weigh out 12 g of iron(III) nitrate nonahydrate.
Add the solid to 1) slowly, stirring to dissolve each addition.
3) Use a measuring cylinder, or preferably a graduated pipette, for
33.0 cc of 10% w/w ammonia solution.
OR 14.5 cc of 24% w/w ammonia made up to 33 cc with water.
OR 13.9 cc of 25% “ “
OR 12.6 cc of 28% “ “
OR 11.8 cc of 30% ” “
OR 11.1 cc of 32% “ “
OR 10.3 cc of 35% “ “
Add it to 2) slowly with stirring; the yellow solution turns green.
4) Weigh out 10 g of potassium ferricyanide, purity 99% preferably.
Add the solid to 3) and stir thoroughly to dissolve all the crystals.
5) Transfer solution 4) to a measuring cylinder or volumetric flask and
make it up with pure water to a final volume of 100 cc. Mix well and
transfer the solution to a well-stoppered brown glass bottle. Label
and date it, and store in the dark.
The solution should be left to stand overnight before first use.
Any trace impurities in the chemicals may cause the formation of a
very small amount of sediment – brown ferric hydroxide and/or
Prussian blue - which can be removed by filtration if necessary.
This sensitizer has a storage life of several weeks at room temperature
but will keep much longer if refrigerated to ca. 5ºC.

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Preparation of ‘One-bottle’ Sensitizers 2 & 3
2. Medium Contrast: Exposure Scale ~2.3
Follow the procedure for 1) and 2) above, then substitute the
following for 3):
3) Use a measuring cylinder, or preferably a graduated pipette, for
38.5 cc of 10% w/w ammonia solution.
OR 16.9 cc of 24% w/w ammonia made up to 38 cc with water.
OR 16.2 cc of 25% “ “
OR 14.7 cc of 28% “ “
OR 13.8 cc of 30% ” “
OR 12.9 cc of 32% “ “
OR 12.0 cc of 35% “ “
Add it to 2) slowly with stirring; the yellow solution turns green.
Continue with steps 4) and 5) as above.
3. High Contrast: Exposure Scale ~1.8
Follow the procedure for 1) and 2) above, then substitute the
following for 3):
3) Use a measuring cylinder, or preferably a graduated pipette, for
44.0 cc of 10% w/w ammonia solution.
OR 19.3 cc of 24% w/w ammonia made up to 44 cc with water.
OR 18.5 cc of 25% “ “
OR 16.8 cc of 28% “ “
OR 15.7 cc of 30% ” “
OR 14.8 cc of 32% “ “
OR 13.7 cc of 35% “ “
Add it to 2) slowly with stirring; the yellow solution turns green.
Continue with steps 4) and 5) as above.
Intermediate degrees of contrast with Exposure Scales
lying between 2.7 and 1.8 can be obtained by mixing
sensitizer solutions 1 and 3 proportionally.

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Equipment and Materials for
Coating and Printing Cyanotypes
Paper: pure cellulose, unbuffered, internally sized with AKD
Glass coating rod or brush
Blotting strips
Syringes or pipettes, Calibrated 2 cc and 5 cc
Glass plate
Spirit level
Drafting tape or clips
Print frame
UVA light source
Timer
Plastic measuring jug 1-2 litre
Stirrer
Processing Dishes (2)
Drying line and pegs or drying screen
Procedure for the ** Cyanotype Process
Choice of Paper
Use only papers that are not alkaline-buffered with chalk (calcium
carbonate). Alkalies are hostile to cyanotype chemistry. The best
results will be obtained on unbuffered papers such as:
• Arches Platine
• Hahnemühle Platinum Rag
• Magnani Revere Platinum
• ‘Buxton’ or 'Herschel' handmade by Ruscombe Mill
• Crane’s Platinotype
• Weston Diploma Parchment
If buffered papers are unavoidable, they should be pre-treated in
a bath of dilute (5% v/v) hydrochloric acid, or 5-10% w/v sulphamic
acid, to destroy the chalk, then washed. The use of oxalic acid is not
recommended because calcium oxalate is as insoluble as calcium
carbonate. For prints up to 10x8 in. or A4 in size, a paper weight of
160 gsm (grams per square meter, g/m2) is adequate. For larger prints
of A3 size, a weight of 240 gsm, or more, will minimise “bellying” of
the wetted area of the coated sheet, which will contact the negative
better and be more robust in wet handling.
Negatives and Control of Contrast
Negatives may have a long density range (in the UV): as much as 2.7,
to produce a full tonal range in a print made with the low contrast
sensitizer. This version particularly commends itself for preparing
digital negatives by the PiezoDN protocols. By making use of the
variable contrast adjustment, sensitizers may be formulated to match
their Exposure Scale to the density range of silver gelatin negatives
prepared for other processes, such as platinotype or palladiotype.
Addition of Su**ctant to the Sensitizer
The success of cyanotype depends on the sensitizer penetrating the
interfibrillar space of the su**ce cellulose fibres, where the pigment
will be trapped, and not simply remaining in the coarse pores of the
paper, from which it washes out. To assist retention and to provide a
more uniformly coated su**ce, a su**ctant (or ‘wetting agent’) is
used. Tween 20™ (a non-ionic su**ctant) is added to the sensitizer
solution just before coating to produce a final concentration of ca.
0.25-0.5%. i.e. one drop (ca. 0.05 cc) of a 5% v/v stock solution of
Tween 20™ is added to each cc of sensitizer and mixed in well. For
larger coating areas, add one drop of a 25% v/v stock solution of
Tween 20™ to each 5 cc of sensitizer. Do not use Tween 80™ which
causes foam. Do not add Tween to the stock sensitizer solution: it
doesn’t last very well when dilute, and the appropriate amount - to be
found by trial - will depend upon the chosen paper.

Coating
Coating by the rod method (ca. 6 ‘passes’) will require ca. 1.5 cc of
sensitizer to coat an area appropriate for a 10”x8" print; brush coating
consumes more. Blot off any excess sensitizer which may crystallize
and damage negatives. Try to “fine tune” your coating volume on the
basis of experience, in order to avoid excess. For instructions see:
http://www.mikeware.co.uk/mikeware/preparations.html
https://www.dropbox.com/s/yf6z1kftk7q2xcf/coating.mov?dl=0
Drying
Let the sensitized paper dry at room temperature in the dark for an
hour or two. Shorter drying times are possible, but very humid paper
may damage silver-gelatin negatives, and not lie flat due to swelling.
Alternatively, allow a few minutes for the sensitizer to soak in,
until the paper su**ce appears non-reflective, then heat-dry it with an
air stream at ca. 40°C for ca. 5 minutes. Heat drying of a cyanotype
paper appears to increase contrast slightly (~1 stop). Prompt drying
can diminish any chemical fogging due to impurities in the paper; but
note that over-rapid drying may diminish penetration and worsen the
loss of image substance during the wet-processing procedure.
The storage life of coated paper depends on the purity of the
paper base, as mentioned above, so use the sensitized paper within a
few hours of coating, if possible. It will keep longer in a cool, dark,
desiccated enclosure. The coated side should remain light yellow: if it
turns green or, worse, blue, the highlights are chemically fogged, so
reject it and find a better paper.
Printing Exposure
Exposure depends on the chosen scale of contrast but is significantly
shorter than that needed for the Classic cyanotype process - probably
about 5 to 10 minutes under an average 365 nm UVA light source (e.g.
a facial tanning unit) should suffice.
Since this is substantially a print-out process, a traditional
hinged-back contact printing frame will enable inspection of the
desired result: the exposure is continued until the high values appear
light green, the mid-tones are firm blue, and the deepest shadow
tones are reversed to a pale blue-grey, giving the image a ‘solarised’
look. If the print is left in the dark for some hours before wet
processing, another stop of highlight detail may become apparent.

Wet Processing
1 Develop in 1% citric acid for half to one minute with agitation –
until Prussian blue starts to runoff, then transfer to the water wash. If
high-lights appear to be unduly blued, use citric acid more dilute than
1%. Omitting this acidic bath and simply processing in water produces
a much shorter Exposure Scale of ~1.3, with higher contrast and no
fogging but a slightly weakened Dmax.
2 Water Wash: immerse face down in gently running water for ~10
minutes. Alkaline water (pH >7) must not be used, nor hard water,
containing calcium salts, which will damage the Prussian blue image.
Alternatively, at least three or four baths of static water may be used.
The reversed shadow tones regain density fairly rapidly by air
reoxidation during wet processing and drying, but if completion of the
regain is required immediately -e.g. for densitometry- then 50 cc of
6% hydrogen peroxide (“20 Volume”) may be added per litre of wash
bath. Blued highlights may be cleared by immersion in a 1% bath of
ammonium oxalate for a few minutes.
Permanence & Stability
The Prussian blue pigment of cyanotypes is destroyed by alkali:
buffered wrappings and mounts (pH > 9) should therefore be avoided.
Cyanotypes can fade somewhat in daylight (2000 lux) or bright gallery
illumination, but this loss is regained on dark storage in the air, and
their full density should return after a few days. Exhibition under low
light levels (50 to 200 lux) should cause no measurable fading. For
conservation information see:
http://www.mikeware.co.uk/mikeware/conservation.html
Summary of ** Cyanotype Procedure
1. Unbuffered paper: choose side, mark up coating area
2. Syringe out sensitizer: add Tween to final strength ~0.25-0.5 %
3. Rod Coat: ~1.5 cc per 10 x 8 in. area: 5-8 ‘passes’ of coating rod
4. Dry in dark: 1-2 hours at room temp, or 40°C air for 10 minutes
5. Negative: density range from 1.8 to a maximum 2.8, in the UVA
6. Expose to UVA: until high values green and deep shadows reversed
7. Develop: ½ minute in ~1% citric acid; or water for more contrast
8. Wash: in non-alkaline, non-hard water for 10 minutes

Typical results for ** Cyanotype: One-bottle version
Three contrast grades 1, 2, 3. Sensitizer pH given.
Buxton paper 160 gsm. Tween20 0.3%. Exposure 8½ minutes.
1-3 developed in 1% citric acid for ½ minute. 4 in water only.

fyly1010

前几天，我还找到一包晒蓝的药包，如果有人想要，免费送出。

hbhero

fyly1010 发表于 2021-1-22 15:58
前几天，我还找到一包晒蓝的药包，如果有人想要，免费送出。

正在琢磨玩玩晒蓝，不知能否给我？

fyly1010

hbhero 发表于 2021-1-23 00:38
正在琢磨玩玩晒蓝，不知能否给我？

我回家找找，找到就给你。但不知道还能不能用，毕竟，时间太长了，

cndby