Vitrolite

For eight decades, from high streets in the UK, Ireland, Europe and the USA to the bedroom of the Maharajah of Indore, this glass product opened up new possibilities.

An advertisement for Vitrolite by the British Vitrolite Company from the Architectural Review in March 1937. Woodhall Garage in Calverley had a primrose Vitrolite front with green Vitrolite stripes and a black Vitrolite plinth.

Vitrolite was a 20th-century glass that transformed certain areas of our architectural landscape. It had a much longer reign than other such inventions, stretching from 1908 to 1990, with its heyday between 1910 and 1970. My interest in it began as a response to its aesthetic character in Irish shopfronts and a piece of casework as a conservation officer in Dublin, which led to a research thesis in 2005-6.

Vitrolite is a coloured, rolled opal plate glass. The rolled nature of it refers to the ridged underside from the rolling of the molten glass after it leaves the oven; the opal quality refers to its opacity, which was a closely-guarded secret; and plate refers to the fact that it was made by casting rather than blowing, as was common for large sheets of glass before the 1959 development of float glass.

Anything published on Vitrolite will date it to the 1920s or 30s, but I found examples that dated to 1908 from both the USA and Europe. While its European origins remain obscure, I unravelled its industrial history from the USA to the UK. In the USA, the Vitrolite Company was incorporated in 1910 to produce the material for structural purposes. Its use spread rapidly to subway stations, bars, hotels and restaurants, its cleanliness associated with a ‘world of sparkling white wherever men assembled for food and drink’. In 1913 the company bought the sole rights to the British Isles, lining a corridor in the Bodleian Library, Oxford, and numerous hospital theatres. Colours were introduced in 1922, and countless adverts targeted the housewife, promoting it for bathrooms and kitchens.

Pilkingtons of Lancashire re-established its architects’ department in 1928 to exploit this new glass. The company tried to manufacture it itself but failed to, instead buying out the Vitrolite Company in 1932. Salesmen travelled round with little boxes of samples; as well as all the translucent glasses they would have Vitrolite in black, white and mint green. They commissioned the book Glass in Architecture and Decoration by Raymond McGrath and AC Frost, still one of the best texts on the subject. Pilkingtons continued Vitrolite production until 1968. Other trade names included Carrara (USA), Marmorite and ‘black polished’ (UK). Vitrolite was used in shopfronts and bathrooms initially in an elaborate beaux-arts style. It was only after the art-deco exposition of 1925 that the aesthetic became sleeker. We should remember how innovative glass for building was at the time – an English commentator at that exposition listed ‘glass walls’ as one of the exotic elements on display (along with sharkskin furniture and monkeyskin bedspreads).

A New Glass Age was being heralded which saw the potential of glass as an indestructible material. It allowed buildings to be made of steel, which could withstand bombing, then be quickly re-enclosed with glass if bombed. The simultaneous rise of the interior designer exulted in the sensuous appeal of glass block, glass mosaic, mirror glass and so on: witness a bed, in green Vitrolite and chrome, for the Maharajah of Indore, 1930–33.

A radical shift happened in shopfront design either side of the first world war. The architectural press decried the large Victorian/ Edwardian shop with its ‘acre-of-glass’ front, favouring the smaller Parisian examples. Shop design became a new specialism, and when architects such as Walter Gropius and Maxwell Fry used a Vitrolite shopfront for the Electricity Showrooms, Cannon Street, London, it gained credence for this new glass treatment.

The largest collection of designs for Vitrolite was the 1935 competition Modernising Main Street, a call for investment and regeneration, to employ architects and lever downtown America out of decline. It linked floor plans to elevations and fitting details. More generally in the architectural press, before and after photos of makeovers with Vitrolite abounded. Particularly clever were those that retained the existing plate-glass windows, which were a very expensive element of any shopfront.

Émigré designer Paul T Frankl stated that ‘Bakelite, aluminium, Monel metal alloy and Vitrolite glass comprised the vernacular of the 20th century’. This pervasiveness lies tantalisingly below the radar of the architectural press and subsequent narratives. In a rare glimpse, the Irish Builder, reviewing the booklet Vitrolite Specifications in 1939, wrote that ‘Vitrolite is now so well-known to the general public, as well as to the architectural professions and cognate trades… in bathrooms, kitchens, hospitals, cloakrooms and lavatories, lounge and cocktail bars, hairdressing salons, shops and cafes, staircases and offices, floor, ceilings and exterior uses such as shop, cafe and garage fronts’.

However, other sources are wonderfully rich, such as photographic collections, including the Scottish Mitchell Library collection. Newspaper items about new Vitrolite shops also bear witness. Records of the (Irish) Department of Industry and Commerce tracked the levying of duties on imports from the UK into Ireland during the ‘economic war’ of the 1930s. Manufacturers such as the UK’s Chance’s and European manufacturers from Czechoslovakia, Belgium and France also corresponded about Vitrolite.

During extensive fieldwork in Ireland recording Vitrolite shopfronts, I identified three main locations for them: the big cities, Dublin and Cork; the main streets of regional towns, at a point in the 1930s–60s when perhaps a new factory or hospital sparked a wave of development; and also invariably in clusters. It was often the ‘big shop’ or department store in a town that led the way, others followed suit and outlived their bigger rival. Jewellers, tobacconists, ice-cream parlours, pharmacies, shoe shops, butchers and bakers all gained Vitrolite. The most common type that survived was the draper’s: family-run, resistant to changes or chain take-overs. This is not dissimilar to the UK, with chains like Austin Reed and Saxone’s being among the early adopters.

The construction details changed over time. Initially only mastic was used to stick the panels to the substrate. McGrath and Frost refer to early failures in Vitrolite cladding in Europe. Later framing systems using clips or metals strips were more durable. The system used meant different aesthetics. The type that survives the most in Ireland uses Staybrite, Birmabrite, polished chrome or bronze framing: this is fixed to a timber frame attached to the building. Vitrolite could be further supported by structural panels behind, such as asbestos-cement. The sequence of erecting the metalwork was critical, keeping the screws hidden. Joints between panels were pointed.

Critical elements of the aesthetic included the ventilation grilles in a variety of art-deco motifs, transom panes in translucent glass, often fluted, and distinctive signage. Other features common to contemporary shops included sun blinds, window enclosures and recessed porches. The stallrisers were of marble, terrazzo and tiles, as well as Vitrolite.

The conservation of Vitrolite is not complicated in principle. As a material it is no longer produced, so every effort should be made to retain it and extend its existence. Ignorance is the biggest cause of loss. Unfortunately, regeneration schemes focusing on high streets do not appreciate mid-twentieth-century shopfronts and often eliminate them, even where there is enough surviving to restore from, and a more ‘traditional-looking’ shopfront is installed.

Physical damage occurs as cracks – from impact, and from thermal stresses in the glass against the frame. Cracks should be filled in; a rule-of-thumb is that if a panel has six or more cracks it should be removed, cut down and redeployed. In larger facades, such as theatres or cinemas, or in interiors, a redistribution of panels can work, with new material inserted as plinths, or bands, to augment the original material. A range of substitute materials exists, from painted render to acrylic or metal panels – all of these fade and stain if used externally.

Interiors have more options. Even glass substitutes, such as panels with enamelled or painted backs, break down very quickly, often within a year of repair. The best substitute is armourclad, which is best used for small areas such as stallrisers, as it does not have the distorted reflectivity of Vitrolite, which is noticeable. It lasts well, however. Shopkeepers I met often had their own small stash of spare panels with which to effect repairs. Panels are traded online through the usual sites and the Vitrolite Man in the USA. The large-scale ‘restoration’ done on the Daily Express building, Fleet Street, London, wastefully got rid of all its Vitrolite.

Contact with shopkeepers whose families commissioned the original front was invaluable. One in Rialto, Dublin, had the original perspective drawings and the accounts for their new Vitrolite shopfront of 1952. The Vitrolite itself was only five per cent of the total cost, with the stainless-steel framing and the plate-glass windows each costing twice as much. The largest cost was for the sunblinds, an element often overlooked today.

Beyond the fascination with the fabric and archaeology of local history, it was intriguing to tease apart the desire to be modern that is represented by the use of Vitrolite on the Irish high street, and even more so the ability to achieve modernity. The application of this new structural glass testified to moments of prosperity, and an aesthetic sensibility that all the orthodox narratives of Irish history and identity ignore and even deny.

Sian Bradley brought a similar lens to bear on the Italian ice cream parlours and cafes that were set up in the Welsh valleys, all using the same Vitrolite aesthetic to dress their new shops. Thus the study of a single material can shed light on a place’s economic and social history, and underlines the importance of retaining that material to continue the understanding of our complicated past.