What substance is used on envelopes to seal them in the old days. Its like a wax

Question:

What substance is used on envelopes to seal them in the old days. Its like a wax. Looking for the real name.?

We have seen movies where a colonial or medieval person is mailing a letter and then seals the envelope with a wax and a stamp. What is the wax and where can you buy these devices and what not?

Best Answer - Chosen by Asker:

wax