Today a customer called who wanted to order a proof of several HKS N spot colours on an uncoated paper. “Which proof profile should I choose? And how exactly can you match my special colours in the proof? I probably have to proof several HKS N red tones in comparison. By the way, the printing is to be done on Fly Cream, a slightly yellowish paper.”
What is the paper white of the production paper?
First of all, I searched with the customer for the production paper in our paper white database. A quick look via full text search revealed that we have measured Fly Cream from Papier Union:

With a B-value in LAB of 9.2, Fly Cream is really not just a little yellowish, as the customer said, but clearly yellowish, chamois, creamy … whatever you want to call it. So it was natural to check the proof profile “ISOUncoatedYellowish”, Fogra 30, to see to what extent the paper white could match.
What is the paper white of the possible proof standard?
Together with the customer we looked up our “paper white of proof profiles” table:

Contrary to the customer’s expectations, the paper white of ISOUncoatedYellowish is not even as yellowish as the paper white of the edition paper Fly cream, which is more yellowish by more than 5 steps on the B axis. So it was clear: PSOUncoated as a brighter-free uncoated paper proof standard is clearly too white, ISOUncoatedYellowish is much more suitable.