About two teaspoonfuls of cudbear into about a quart of boiling water; let it simmer a few minutes before you put in the feathers.
"Enquire Within Upon Everything" by Anonymous
About 130 tons of cudbear are imported annually from Sweden.
"The Commercial Products of the Vegetable Kingdom" by P. L. Simmonds
This was called Cudbear.
"Vegetable Dyes" by Ethel M. Mairet
Cudbear and litmus are of similar origin.
"The New Gresham Encyclopedia. Vol. 1 Part 2" by Various