Grills were a method of breaking up the paper fibers. This allowed the ink in the cancellations to soak into the paper and made it harder to 'wash' the ink off of them.
In many cases the 'secret marks' were not the results of the post office, but the private printers that were hired to print the design.
Mauritius 'Post Office' stamps was created in 1847.
These were provisional issues. The post office did not know what price Congress was going to let them raise the price to, so they printed stamps without a value. You can find the face value on the USPS web site and in catalogs.
No, you can not resell your stamps back to the post office.
In the US there were 7 cent stamps printed. Many of the definitive series of stamps included all denominations from 1 to 20 cents and then every 5 cents after that. And the Postcard rate for part of 1975 was 7 cents.
If you are a philatelist, you can purchase stamps from all over the world on eBay. There is also an official website for the Indian Post Office called e Post Office, and there you can purchase stamps online.
No they will not buy back stamps
Stamps are printed using metal plates. The plates are marked with a number on the margins. A plate block consists of the stamps adjacent to that number in pairs, usually four or six stamps.
Date stamps are available at most office supply stores. Office Max, Office Depot and Staples all carry date stamps. Target and Walgreen's are also places to look for a date stamp.
The Stamp Act required that all materials printed in the colonies be printed on paper embossed with an official revenue stamp or mark. These printed materials included magazines, newsletters, legal documents and newspapers. A fee was charged for that mark. Stamps like you put on a letter were not created until 1840.
Yes, they will exchange damaged stamps for similar stamps. They will not give you back you money.
It is called a stamp album. They can be purchased in a wide variety of styles and costs. The most expensive contain a mount for each stamp already on the page, so you all you have to do is slide it in. Others contain some printed pictures and you past the stamps in with hinges.