Photo Fixer Sodium Thiosulfate, High Purity for Film & Paper.

Product Overview

Our Sodium Thiosulfate (Na₂S₂O₃), commonly known as "Hypo" or photographic fixer, is a high-purity crystalline compound widely used in photographic processing, water treatment, and chemical industries. With excellent reducing properties and solubility, it serves as a versatile chemical across multiple applications.

Technical Specifications

✅ Chemical Formula: Na₂S₂O₃
✅ Purity: ≥99% (Anhydrous)
✅ Appearance: White crystalline powder
✅ Solubility: Highly water soluble
✅ pH Value: 6.5-8.0 (5% solution)
✅ Packaging: 25kg/bag or customized options

In the chemical darkroom processes of traditional photography (film and paper), Sodium Thiosulfate holds a decisive role as the core component of the fixer. Its primary function is to dissolve the unexposed silver halide crystals on the film or paper, which remain light-sensitive after development. If not removed, these crystals would eventually cause the image to turn completely black. Sodium Thiosulfate reacts with silver halide to form stable, water-soluble complexes [Ag(S₂O₃)₂]³⁻, thereby completely washing these unexposed silver salts from the photographic material, permanently fixing the developed image. For photographic artists and darkroom technicians, the purity of the fixer is paramount. Our high-purity Sodium Thiosulfate is free from contaminants like heavy metals and sulfides, ensuring the fixing process does not introduce stains, impurities, or cause image yellowing and fading during long-term storage. It can be used to prepare an acid-hardening fixing bath, which hardens the gelatin emulsion layer during fixation, reducing physical damage during handling. Whether processing black-and-white or color materials, a pure, fresh Sodium Thiosulfate fixing bath is fundamental for achieving the best image texture, tonal range, and archival stability. Used correctly, your photographs will withstand the test of time, remaining clear and vivid for decades.

Why Choose Us?

✅ High-purity products, in compliance with international standards
✅ 30+ Years Chemical Manufacturing Experience
✅ Strict QC with Batch Traceability
✅ Global logistics, supporting sea and air transportation
✅ Technical support, providing customized solutions
✅ Factory direct supply, with strong price competitiveness