rag fibres

Ingredients

linen rags, hemp rags, alum, rosin, iron

Preparation Steps

Original Recipe Text

Islamic papers were generally produced using linen and hemp rags with long fibres (p. 333). After maceration and beating, sheets were formed in moulds. For sizing, the recipe included surface application of egg white or starch blended with alum (hydrated potassium aluminium sulphate) (p. 334). In the deteriorated folios, rosin was specifically identified in the sizing (p. 339). The paper was burnished using stone or glass to render a smooth surface (p. 334).

Evidence

"The Micro-chemical Herzberg test indicated rag fibres in the paper used for the Koran, while the Raspail test #1 revealed rosin only in the sizing material of the deteriorated folios. SEM-EDS identified the presence of iron in all layers of the deteriorated folios but not in the stable folios."

Remarks

The study identifies that the deterioration in 28 specific folios was caused by acid-catalysed hydrolysis (due to rosin) and oxidation processes promoted by iron ions (p. 331, 349). These folios showed significantly lower pH (3.74) compared to stable folios (4.44) (p. 340). The deteriorated folios were previously repaired using the 'vassale' technique (inlaying text in new frame papers) (p. 332).