Aldehyde tanning is a process that uses a combination of glutaraldehyde or oxazolidine that reacts with the hide protein to prevent putrefaction. It is typically used when chrome-free leather is specified. The hide is a cream or white color in its raw state and is often referred to as “wet-white” leather. The aldehyde chemicals can be combined with emulsified oils to produce soft and very absorbent leathers that can be washed by hand or machine.