They have also a perfect mania for coats of arms. If a death occurs in the family they are not satisfied with putting their servants into mourning, they consider that even their residences must bear a distinguishing sign of respect for the arms-bearing departed. On numerous houses one can see lozenge-shaped armorial shields painted on canvas and called hatchments, which are placed over the doorway, and there they remain fro a whole year. And if by any chance the house is let meanwhile, which constantly happens, the tenants take on the sign of mourning with the lease, though they are in no way related to the deceased.
Francis Wey, A Frenchman Sees the English in the Fifties, 1935
see also Cassells Household Guide - click here
see also Mrs. Panton in Leaves from a Life - click here
[on the funeral of Prince Albert, ed.] The day was observed throughout the realm as one of mourning. The bells of all the churches were tolled, and in many of them special services were held. In the towns the shops were closed, and the window blinds of private residences were drawn down. No respectable people appeared abroad except in mourning, and in seaport towns the flags were hoisted half-mast high.
Richard Davey, A History of Mourning, 
Jay's London General Mourning Warehouse, Regent Street, an
establishment which dates from the year 1841, and which during that period has
never ceased to increase its resources and to complete its organisation until it
has become, of its kind, a mart unique both for the quality and the nature of
its attributes. Of late years the business and enterprise of this firm has
enormously increased, and it includes not only all that it necessary for
mourning but also departments devoted to dress of a more general description,
although the colours are confined to such as could be worn for either full or
half mourning. Black silks, however, are pre-eminently a speciality of this
house, and the Continental journals frequently announce that "la maison
Jay de Londres a fait de forts achats." Their system is one from
which they never swerve. It is to buy the commodity direct from the
manufacturers, and to supply it to their patrons at the very smallest modicum of
profit compatible with the legitmate course of trade. The materials for
mourning costumes must always virtually remain unchangeable, and few additions
can be made to the lists of silks, crapes, paramattas, cashmeres, grenadines,
and tulles as fabrics.
The fame of a great house of business like this rests more upon its integrity and the expedition with which commands are executed than anything else. To secure the very best goods, and to have them made up in the best taste and in the latest fashion, is one of the principal aims of the firm, which is not unmindful of legitimate economy. For this purpose, every season competent buyers visit the principal silk marts of Europe ...
Private mourning in modern times, like everything else, has been greatly altered and modified, to suit an age of rapid transit and travel. Men no longer make a point of wearing full black for a fixed number of months after the decease of a near relation, and even content themselves with a black hat-band and dark-coloured garments. Funeral ceremonies, too, are less elaborate, although during the past few years a growing tendency to send flowers to the grave has increased in every class of the community.
Richard Davey, A History of Mourning, 
The depth of black borders on note-paper when a relative had gone was a matter for nice adjustments by experts; in its most acute form it nearly covered the surface of the envelope, and, during the period of sorrowing, it was forbidden to use red or even violet sealing-wax. Monograms were quite indispensable on the flaps of envelopes, and sentimental folk set there, too, a representation of their favourite flower, or, circumstances permitting - as in the case of Rose or Ivy or Violet - an indication of their Christian name. As to the mourning cards, sent out so religiously, one cannot think of them and their extraordinary verses without a shudder.
William Pett Ridge, A Story Teller : Forty Years in London, 1923