877u

Letterpress, silver and uncoated stock

Hi,
I plan to letterpress-print a Xmas card and have a difficulty deciding on the colour. I thought about using Pantone 877U or Black 7U.

The card will be printed on a 100% cotton stock and printer claims silver (PMS 877) doesn't look silver but greyish due to the paper high absorbability factor. However, I've found an [[http://cloudery.wordpress.com/2009/02/21/spiderling-cloud-letterpress-ed...|example]] online that looks quite good...

I haven't seen any sample myself and don't have time to organise one so I have to trust someone... Anyone have an opinion on how silvery the uncoated silver is? Anyone used 877 or Black 7 on 100% cotton paper? Does it look different form normal grey/black? Would you recommend using it?

Thanks in advance!
Aleksander