Description:

Using Block

In conventional stop baths, the acid ingredient which stops development is hazardous,
unpleasant to use and can damage prints. Acid can break down print sizing which normally
protects fibers from fixer thiosulfate contamination, a major cause of deterioration. Plain water
stop baths eliminate the side-effects of acid, but do not stop development as effectively, and
can cause stains, emulsion swelling and reticulation.

Block is an acid solution, but the acids are buffered to minimize the side-effects. Buffering
protects print fibers for greater permanence, reduces emulsion swelling, staining, reticulation
and eliminates odors. Block will also prevent carbonate gas ruptures of films (pinholes)
when used as directed.

Block is the basic stop bath for all Sprint Systems processes. Always use Block
Stop Bath before fixing with Alum Hardening Converter to provide the correct acid value.

One liter of Block Stop Bath concentrate will make 10 liters of working solution, enough to
process (600) 8x10 fiber prints or (900) 8x10 resin-coated prints or (600) rolls of 35mm, 36
exposure film.

Exhaustion Indicator

BLOCK Stop Bath working solution changes color from yellow to lavender as it approaches
exhaustion in B&W printing. When printing with Quick Silver Print Developer, Block
Stop Bath and RECORD Speed Fixer mixed in equal volumes, Block Stop Bath's color
indicator will signal the simultaneous exhaustion of all three solutions.

How To Mix

Dilute Block concentrate 1:9 with water to make the desired volume of working solution.

For Example:

100ml Block Stop Bath Concentrate

+ 900ml Water

= 1000ml Block Stop Bath Working Solution

Stop Bath Procedure

Use Block Stop Bath working solution at the same temperature as the developer solution
unless otherwise directed in your processing instructions.

For Films: Immerse for at least 1 Minute with continuous agitation. For Prints: Immerse for at
least 5 Seconds with continuous agitation.

Hardening Stop Bath

Block Stop Bath may be converted into a hardening stop bath for sepia toning, or to
replace hardening in the fixer if sulfur dioxide vapors must be minimized. Substitute the
following converted working solution for the normal stop bath and immerse films or prints for
3-6 minutes with agitation.

For Example:

40ml Block Stop Bath Concentrate

60ml Archive Fixer Remover Concentrate

900ml Water

+ 30ml Record Alum Hardening Converter Concentrate

= 1030ml Hardening Stop Bath Working Solution

When mixing other quantities of hardening stop bath, please be sure to maintain the correct
proportions and order of procedure described above.

Capacity & Indicator

One liter of Block Stop Bath working solution will process at least (60) 8x10 fiber prints or
(90) 8x10 resin-coated prints or the equivalent of (60) rolls of 35mm, 36 exposure film.

Shelf Life

Stored as concentrate or working solution, with or without air in the container, Block Stop
Bath has a shelf life of at least 2 years.



Mfr.#SB001-R