This is "Standard" size Goshuincho book
 
Measurements : 18cm (7in) x 12cm (4 3/4 in), thickness 1.3 cm (a half inch)
Book is accordion-fold binding. Japanese thick WASHI paper used.
 
Covering is plain white fabric. Looks silk. but might be polyester silky fabric.
In anciet Japanese, white is also sounds as "aka", which is means "red" now.  "Aka" is from "akarui", blight, "akari" light. So the white is also for protect color as red. And the symbol of your pureness.
 
Thank you for dropping by!
Natsu