Note: I've changed the water test to the bottom of the review. Saves some paper.
My thanks to Marty for the ink samples!
Chesterfield is an American brand of ink made by either Private Reserve or Diamine. It’s not a super well known or popular ink. There is no real consensus though more lean towards Diamine. It seems that xfountain pens used to sell these inks but now xfountain pens’ website now re-routes to the Birmingham Pen Company. However they don’t sell any Chesterfield ink. Now putting that aside, Chesterfield Antique Oxford is a bold and bright blue ink with a red sheen. Plus it also shades very well. Chesterfield Antique Oxford is a lubricated blue ink that flows well.