2.1 – Alicatado technique
The original technique used to produce tile panels was the “Alicatado” technique. Alicate is the Iberian word for pliers and derives from the Arabic word ‘allikkát’. Each clay square was fired in a single glazed colour and then cutted in small pieces by a plier. To create abstract geometric patterns were assembled the cutted small pieces of different colors. This technique was not far from the Roman way of building their famous mosaics.
The next picture was taken at Sintra National Palace, and this specific tile panel from the beginning of the XVI century was made using a blend of two different techniques: Alicatado and Dry Cord.
https://www.parquesdesintra.pt/en/parks-monuments/national-palace-of-sintra
2.2 – Dry Cord technique
There is no certainty when this technique was adopted by the Iberian workshops, but it was a major improvement on the production.
When fired the coloured glazes had the tendency of running out of their design. The Dry Cord consists to isolate the different coloured glazes with a thin line filled with a greazy substance and mixed with a dark pigment to make these lines visible ( it can be for example soaked cord with linseed oil and manganese oxide). With this technique the tiles workshops improved their productivity and by the end of the XV century the Alicatado techinique was almost abandoned.
The next panel, located at the National Azulejos Museum, was created using the dry cord technique.
https://www.museunacionaldoazulejo.pt/en/sala-tecnicas
2.3 – Gable technique
A different approach but the same goal. By using molds on fresh clay before the first firing, craftsmen created barriers to prevent the colored glazes from running beyond their design. Naturally, these tiles always had some texture from the gables, and the trim was far from perfect. However, productivity increased, and so did demand.
These three techniques had a common foundation: pigments (metal oxides) in powder form. With the arrival of the Majolica technique, these oxides were diluted, becoming similar to regular ink. This feature provided artisans with much greater flexibility and attracted professional painters.
Next panel, located at Bacalhoa palace in Azeitão, was created using the Gable Technique.
https://bacalhoa.pt/en/history-of-bacalhoa
2.4 – Majolica technique
Majolica originated in Italy but later migrated to Flanders. From there, Flemish artists arrived in Lisbon, establishing a production center that has lasted to this day. Majolica was a game-changer for the industry. Scholar painters began using tiles as a medium to express their creativity, as the Majolica technique allowed them to paint directly on each tile, greatly expanding artistic possibilities.
This technique involved applying a tin glaze (a mixture of tin, lead, quartz sand, and salt) over the fired clay. The tin glaze needed to be moist, with a creamy consistency, to absorb the liquid colored glazes used for painting the tile. After firing, the tin glaze transformed into a translucent layer, allowing the underlying colored glazes to appear. In conclusion, the tin glaze was transformed by the fire into a vitrified layer, with the painted depiction beneath becoming visible through it.
Next panel, located at Saint Roque church in Lisbon, was created using the Majolica technique.
https://museusaoroque.scml.pt/museu-igreja/capela-de-sao-roque
