I print my ham radio QSL cards with a laser printer on card stock. I'm doing a new run of them and since they will be written on with FP, I did some ink tests.

Paper: Xerox 110 lb card stock, canary yellow.
Inks tested: Noodlers Bulletproof Black, Fox Red, Hunter Green, Mix of Golden Brown and Black. Note that Hunter Green and Fox Red are quite feather-prone.

Front and back sides of paper extremely smooth writing. Very pleasant, good ink acceptance.

Front side feathering:

Black none
Red very minor
Green very minor
Brown none

Back side feathering:

Black none
Red moderate but acceptable
Green moderate but acceptable
Brown none