Design and Manufacture

The exact form of the blue plaque, as we see it now, was a relatively late development, though certain guiding principles had been in place from the outset. The earliest plaques, erected in 1867, were blue. Their format, a circle with the name of the Society of Arts worked into a pattern around the edge, was used consistently by the Society over its 35 years of management.
However, colour varied; the manufacturers - Minton, Hollins, and Co. - found it difficult and expensive to produce blue coloured plaques, and most of those set up before 1900 were of a chocolate brown hue.

After taking over the scheme in 1901, the London County Council chose to use the Society of Arts design as a model, merely substituting its own name for that of the Society. Plaques remained, on the whole, circular and, like the Society of Arts's plaques, were made of ceramic by Minton. The first LCC plaques erected in 1903 had a laurel wreath surround, with ribbon embellishments, a design used consistently until 1938. However, experimentation was carried out regularly until the 1920s; plaques were made in bronze, stone and lead, some designed as squares or rectangles, and varied in colour between blue, chocolate, sage and terracotta.

In 1921, there was a move towards standardisation. Blue was chosen as the principal colour, though subject to variation 'in any special case', and Doulton ware was made the norm. In 1938, the modern design of the blue plaque was born. This omitted the wreath and ribbon motif, and simplified the overall layout, allowing a bolder spacing and arrangement of the lettering. The first plaque made to this design commemorated composer Wolfgang Amadeus Mozart (1756-91). The white border was added shortly afterwards, and the adoption of the colour blue, used almost invariably from the 1940s onwards, completed the now-familiar design.

Plaques continued to be made by Doulton until 1955, when the firm's London factory closed and manufacture was moved to Poole, Dorset. Since 1981, manufacture has been undertaken by independent craftspeople.

Once the inscription of a plaque has been agreed, a design is created, placed and set by our designer using English Heritage's own font. In order to be legible, this design usually takes up to 20 words of inscription. On occasions, both design and material can be altered.

Manufacture of each plaque is undertaken by the mixing and pouring of a thick clay slip into a casting mould. When sufficiently dry, the cast is removed and the outline of the inscription and border is piped onto the face of the plaque. The plaque is fired, and glaze is applied: white for the letters and border, and blue for the background. The plaque is then fired for a second time. The process produces gently raised characters and border, a unique feature of English Heritage plaques. After firing, plaques usually have a thickness of 2 inches (50mm) and a final diameter of 19½ inches (495mm), although smaller diameter plaques are sometimes used to meet special circumstances.

Plaques have been found to be extremely durable and have an almost indefinite life expectancy. Similar plaques erected by the Society of Arts have lasted, perfectly legible, for over one hundred years. Due to the slightly domed design, they are self-cleansing and require virtually no maintenance.