This is 10g of Sodium Bisulfite from Photographers' Formulary. It is commonly used as an acidic additive in fixer baths as well as a preservative for various pyro developer solutions.

Acidic Additive for Fixer Baths    Preservative for Pyro Developers

Related Questions and Answers

Q: 1. What country is it made in?

A: The Photographers' Formulary Tyvek Apron is made in China.

Q: 2. I have used TF-4 in the past. What is the difference between TF-4 and TF-5 fixer?

A: From PF's website; TF-5 is an extraordinary fixer for both paper and film. * Processing time of only 30 seconds for resin-coated prints, 60 seconds for fiber-based prints, with no hypo clearing agent necessary. * No stop bath necessary. Just use water rinse after developing. * Non-hardening. Excellent for use with prints to be toned or re-touched. * It is a near neutral fix that changes the pH of the film or paper from alkaline to near neutral, unlike TF4 in which the film or paper stays at an alkaline pH value. * The only rapid-fixer system that allows the print to be completely fixed without impairing the rapidity of the wash. * No image bleaching. All conventional fixers act as reducers. This means that the longer the material is left in the fixer, the more image silver is destroyed. This can only have bad effects on the image, whether it is a print or a negative. Conventional sodium thiosulfate (rapid) fixers suffer from this defect especially. The problem is eliminated in TF-5, which may offer slightly richer maximum blacks as a result.

Q: 3. Can I use this to replicate sweat on an athlete photo shoot?

A: Yes, you could use glycerin to replicate sweat on an athlete during a photo shoot.

Q: 4. Do I need to mix with water? Does it comes in spray recipient?

A: The Photographers' Formulary Glycerin (100mL) needs to be diluted in water. Since this is a concentrated formula, the spray trigger cap is not provided with this bottle.

Q: 5. is the carbon black made from burning oil or is made from charcoal ?

A: Unfortunately the manufacturer does not specify this and could not provide any info as to which process was used to make this.

Q: 6. What are the outside dimensions of the 8x10" frame?

A: The Photographers' Formulary Select Contact Print Frame (8 x 10") has outside dimensions of 14x16 inches.

Q: 7. Can u get this in bigger size?

A: We do carry a 1.1 (4000ml) gallon version from the same manufacturer, here: https://bhpho.to/2UNUhAp

Q: 8. How many microns is the particle size? (Air float does not seem to have a distinct measurement)

A: I contacted Photographer's Formulary with your inquiry. They state that unfortunately, they do not have the particle micron size information available for this item. The only size indication they have is the "air float" description.

Q: 9. Can this product be used for Lith developing?

A: Photographers' Formulary Potassium Bromide can be used as an ingredient for lith developer.

Q: 10. What colors does it come in?

A: Black. This product just comes in black, as listed in the description. Good for light sensitive chemistry.