Ciba has always had a short working life once opened. There is a gradual shift in color balance as the paper ages, with increasing risk of highlight crossover as the paper gets overripe. This happens within the first six months after thawing. I carefully selected my chromes and their masking protocol for the ideal time the paper would match what I was trying to accomplish, and even used the tendency to crossover creatively, for very subtle control of highlight characteristics. It was many of the special techniques I learned. Now I'm relearning everything anew with Fuji Supergloss, which achieves a similar look but begins with a color neg, and requires very different kinds of masking options than Ciba did. Same equipment, however. But alas, when I pull out some of those very first Ciba prints I made when this product first came out, it looks like they were made yesterday. As vibrant as day one.