The fabrics were printed in reserve using pad molds covered in glue or resin (reserve printing), so that these sections of fabric remained the original color (usually white). Once the glue or resin was dry (3-6 months) the fabrics were immersed one or more times in the indigo dye bath for a duration of 30-45 minutes. Indigo, unlike other dyes, is composed of molecules that are insoluble in water and therefore in order to dissolve it needed the addition of ash or other substances, which made the bath yellow-green. For this reason, the newly dyed fabric was initially yellow-greenish in color and only with drying and the consequent reaction of the pigment with oxygen (oxidation) did it transform into indigo blue. Once dried, the fabrics were immersed in a bath of boiling water or in acid solutions with the aim of dissolving the glue present on the uncolored part of the fabric (reserve).
The result was an indigo blue fabric with white decorative patterns.