Retanning agent to be used in rechroming and neutralizing SYNTAN A is a retanning agent to be used in rechroming and neutralizing. Suitable applications include: shoe upper, bag leather, garment and upholstery. Bags & leather goods Garment Shoe Upper SYNTAN A improves grain tightness while at the same time it increases softness and fullness. Leathers retanned with SYNTAN A are dyed in level and full shades. TDS request Request a TDS of product TDS Sample request Request a sample of product Request