1841 Penny Red on cover

I have yet to receive a Penny Black or a Two Pence Blue that is tied to a cover; these were the first two stamps in the world, issued in 1840 (May 06 and May 07, respectively.). To date, my oldest stamp on cover is a British Penny Red issued in 1841 (Scott 3, SG 8).

1841 Penny Red on cover sent in the 1850s.

The Penny Red was the main type of postage stamp in Great Britain and Ireland until 1879, with only minor changes to the design during that time (e.g. paper color, perforation, watermark, inclusion of plate numbers, letters at the corners). The colour was changed from black to red because it was difficult to see a cancellation mark on the Penny Black. On the other hand, a black cancel was easily visible on a Penny Red. 

The Penny Reds issued in 1841 had no perforations, and had to be cut from the sheet using scissors in the same manner as for the Penny Black and the early printings of the Two Pence Blue.

The exact year of mailing is still a mystery because the last digit of the year in the cancellation is illegible.

The mailing rate at that time was 1 penny for inland letters not exceeding 1 ounce in weight. Postcard swappers/collectors might be interested to know that a reduced postcard rate was only introduced on October 1870; postcards (inland) cost 1/2 penny to send.