It is 100 lb/150 g/m vellum paper that appears to take pen, pencil, ink and watercolour washes without difficulty. It is a strong ivory colour and pleasant on the eye after adding line. The sketchbook contains 62 sheets/124 pages. It appears both sides of the paper can be used without much bleed through or reveal.
Orchid on dining room table,
Stillman and Birn Gamma 4x6 sketchbook
drawn with Safari (F) pen and J. Herbin Noire ink
I like the feel of the book, the paper and even the size, but this small version does not lay flat as you an see from the photo above. I understand that the larger versions do.
The US based company has four other lines: Alpha, Beta, Delta and Epsilon, each with different paper.
I hope to test drive my paper samples in the coming days and report back on their response to my usual media.
These sketchbooks are available at Utrecht and Wet Paint; Stillman and Birn have a good looking web site describing their origin and their papers.