Stained Glass Triptych

The Dyeing Trade

Calderdale once produced more fustian clothes than anywhere else on earth. Over the past hundred years the mills have gradually been converted into homes, offices, workshops and, particularly in Hebden Bridge, into artist studios.

Yet the cacophonous churn of the textile mill and ammoniacal tang of the tanneries has not vanished completely. Even today echoes of industry can be found in artwork produced under the same roofs.

This exhibition continues that theme. Commissioned by the Worshipful Company of Dyers and designed and produced by two Hebden artists, Phil O'Farrell & Karl Theobald, it commemorates the vast Yorkshire textile dyeing industry that dominated our valley 150 years ago.

Shown through a series of large stained glass panels, visitors will learn how North Sea kelp, Yorkshire shale and London urine (!) were combined to form alum, the essential fixative used for dyeing clothes and indeed, stained glass windows.

You will also see stained glass manufacture in person as Karl constructs the final window of the series in the gallery itself.

We really hope you can make it! 11am - 4pm, Saturday & Sunday 27-28 January, 2018.

Watch Trailer



Hangingroyd Lane, Hebden Bridge, HX7 7BZ

Northlight Artspace is the small gallery attached to the back of the Northlight Art Studios. It will be open to the public from 11am until 4pm each day of the show.

Northlight is an accesible venue. You can find the step-free entrance on the corner of Hangingroyd Lane and Baker's Street.

For more information about Northlight, please visit

The Journey of Alum

The series of stained glass windows aims to tell the tale of alum, the essential mordant used in c18 dyes.

Please click on the categories below to explore the journey and read brief extracts from the exhibition.

Alum production from Yorkshire slate required large quantities of human urine. At first this was obtained locally, then further afield - from Newcastle to Hull. Eventually the industry became so large that barrels had to be shipped from the capital.

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    Full buckets were left on London street corners ready for collection by night soil men

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    Pinnaces were used to load the barrels onto collier brigs at the Pool of London

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    The brigs would bring coal from Yorkshire and make the return journey laden with the offending barrels, leading the sailors to be accused of taking the piss

Alum's three key ingredients were ammonia, potassium and aluminium sulphate, obtained from urine, seaweed and shale respectively. They were all transported to vast alum houses along the coast of East Yorkshire.

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    Barrels of stale urine and crates of toasted kelp were winched up the cliffs at Robin Hood's Bay. These provided the first two ingredients of alum: ammonia and potassium

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    Shale was quarried and roasted at Ravenscar in huge piles called clamps. Adding water to the red hot rock produced the third ingredient: aluminium sulphate

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    These were all combined and allowed to crystallise. To prevent crystals of ferrous sulphate from forming fresh hens eggs were added to the solution to test its density.

Alum was packed and shipped to dyers and tanners around the country.

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    Rolls of cotton were passed through troughs of alum solution. The fabric was then immersed in vats of dye. The initial fixing process keeps natural dyes from being quickly washed out.

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    Dresses were dyed using Yorkshire alum as a fixative until well into the nineteenth century.