How easy is it to make animal horns transparent? I never knew that HORN in HORNbook refers to animal horns, or animal horns can be made transparent? If Medievalists can make it transparent, the transparency process must've been cheap easy and quick, right?
The Horn Book | Why is it called &quot;The Horn Book&quot;?

Back in the sixteenth century, English monks began to make hornbooks to help their pupils learn to read. Usually a wooden paddle with an alphabet and a verse glued to the surface, hornbooks derived their name from the piece of transparent horn protecting the verse. The picture to the right shows a modern replica of a hornbook.

Hornbook - Wikipedia

A hornbook is a book that serves as primer for study. The hornbook originated in England as long ago as 1450,[1] or earlier.[2] The term has been applied to a few different study materials in different fields. In children's education, in the years before modern educational materials were used, it referred to a leaf or page displaying the alphabet, religious materials, etc., covered with a transparent sheet of horn (or mica) and attached to a frame provided with a handle.[3]
I found this description of how the horn is prepared in a post by Tammy L. Austin, at the University of Notre Dame's website (https://www3.nd.edu/~rbarger/www7/hornbook.html):

The horn of oxen and sheep were used to make the laminating structure. The horn was left in cold water for several weeks, which separated the usable part from the bone. It was then heated, first in boiling water then by fire, and pressed by plates and machines to make it smooth and transparent.