Flannel was Wales' biggest cloth industry, made mainly around Welshpool and dyed blue, drab or brown. This may be why blue was recognised as a popular colour worn by men and women alike in Wales.

From the 1880s, when the traditional costume had gone out of general use, selected elements of it became adopted as a National costume worn at eisteddfods and on special occasions. It was first worn by girls as a celebration on Saint David's Day just before the First World War.

Cyfarthfa Castle Museum and Art Gallery holds Welsh textiles from the 19th century up to the 20th century in the collection.