To facilitate the use of aqueous curative treatments such as calcium phytate treatment on heavily damaged documents, we defined a simple method to evaluate quantitatively the formation of cracks. This method was experimented on laboratory samples made of Whatman n°1 paper squares on which a 0.1 ml drop of ink was deposited. After artificial ageing, the inked paper became brown and very brittle, whereas the virgin paper remained resistant and elastic. Several series of 30 samples were submitted to different immersion procedures, performed in glass containers on a light table. Pictures were then taken at each phase of the treatment. By counting the apparent cracks we could then compare different handling procedures, and select the least destructive. Finally, the selected procedure was tested on an original sample, leading to satisfactory results.