Keyed color processes

Avoiding distractions

Dithering and the ink/pigment print. Pounding one contrast into another.

karoshi”, or “death from overwork”

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Three Letters… Separated by amateur hours:

did he gain clarity, typing skill, or something else.

Note: the used acronym, in photoland is BZT, or BZTA, not BTZ. The enthusiastic expert (above) is typing, or thinking, out of sync. Chemists often use BZT as shorthand. The less used form, although the one preferred by emulsion chemists is: BTAZ 

As in:

Do not use denatured alcohol, as the denaturant can be harmful to photographic processes.

Do use alcohol, iso propyl alcohol or other water miscible organic solvents. I usually use 1% in DW though.

For a 2% solution of BTAZ in alcohol use 2 g BTAZ in 98 g alcohol. This makes 2% wt/wt BTAZ in solvent.

This is true for any mixture regardless of density. That is why weight is better than density.
Be cautious in handling benzotriazole, especially in powdered form. It is extremely toxic so avoid inhaling the powder particles. I recommend you download the MSDS before using.
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The effects of benzotriazole and bromide are more. detectable at low densities. This is obvious with the observed values for base plus fog. As development time increases or  when agitation is employed the effect of bromide becomes insignificant compared to that of benzotriazole as the density continues to build up with time, the effect of the benzotriazole level ceases to be a significant factor in the resulting contrast and speed values. 

benzotriazole has an effect on the developed density levels with Increasing development time. This is more evident at the lower exposure levels. 

common acronyms to facilitate discussion.

TAI: 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene
PMT: 1-phenyl-5-mercaptotetrazole
2-MBI: 2-mercaptobenzimidazole
6-NBI: 6-nitrobenzimidazole
MBTA: 5-methylbenzotriazole

Sodium carbonate (anhy)	10 g
Benzotriazole	10 g
Water to	1 litre

[sidebar on use in film is in my PanF for masking post ]

Dmax of BW paper.

is determined by the paper. The shape of the curve is altered by development. Kodak D-72 (Dektol) can be used as a reference developer when discussing curve shape. Reproduction image used by the eye is based upon toe and shoulder shape. Sharp shoulder and high Dmax is less often chosen that a softer shoulder with lower Dmax. Open shadow seems darker even with the same Dmax. Usual Dmax of glossy paper is 2 -> 2.3; with matte paper is 1.8-> 2.0. Specialty papers (lithography) have Dmax of 3.2

Goniophotometry: the measure of density as a function of angle of light and viewing system