Limewater absorption and calcite crystal formation on a limewater-impregnated secco wall painting

Abstract

The poorly-bound paint layer on a sixteenth-century lime-based wall painting was impregnated with limewater in an experiment designed to quantify the amount and rate of absorption of the impregnant. A positive consolidating effect was obtained. Results were noticeable 80 days after completion of the treatment. The examination of the surface by scanning electron microscopy showed no calcite crystal formation 14 days after treatment, but revealed dense crystal growth after 80 days.