Retreatment of a Print Damaged by Excessive Sodium Borohydride Bleaching

An etching that was visibly damaged as a result of previous bleaching with a 5.6 % aqueous sodium borohydride solution underwent retreatment involving washing to stabilize the embrittled paper and to remove potentially present bleaching residues. During a final immersion in a dilute calcium hydrogen carbonate solution administered for deacidification, an unexpected and severe blistering occurred that is explained as a recurrence of previous bleaching-related blistering. The blisters were laid down. The treatment concluded with a consolidation of the bleach-damaged paper surface using a 0.5 % gelatine solution applied by misting.

Stabilisation Treatments with Aerosols: Evaluating the Penetration Behaviour of Gelatine and Methylcellulose

In the stabilisation of unbound paint layers on paper and fragile papers with misted adhesive solutions, the distribution of the consolidant determines whether the stabilisation treatment is effective. Knowing the distribution of the adhesive throughout the pigment-paper matrix is therefore crucial. It was studied by labelling gelatine and methylcellulose solutions with fluorescent dyes. Their distribution was analysed in thin sections by fluorescence microscopy. The penetration of the misted 0.25-1% adhesive solutions into powdery pigment layers was investigated by simulating gouaches and pastels with a low ratio of binding agent vs. pigment. The penetration of these dilute adhesives into paper substrates was evaluated using four types of paper with different porosities. The following application techniques were compared: repeated applications with and without intermediate drying, applying the aerosol on the suction table and adding alcohol to the consolidant to decrease its surface tension. The results show that the distribution of misted adhesives is governed by the method of application. Drying between applications diminished the penetration of a 1% gelatine solution. The penetration behaviour of the misted adhesives was influenced by the water absorbency of the paper. Porous papers are completely saturated by 0.5% gelatine solutions. On samples with a low porosity, the adhesive was deposited mainly at the surface. Immersing the papers in 0.5% solutions of gelatine or methylcellulose always led to a full penetration of the paper with the adhesive, regardless of the water absorbency of the paper. Aerosol misting allowed a highly localized precise application, making it a suitable method for local stabilisation of media and paper.

Blood Supply of the Subcutaneous Tissue of the Upper Limb and its Importance in the Subcutaneous Flap

Vascularization of the subcutaneous tissue of the upper extremity is described. Injection of coloured latex or India ink and gelatine solution showed the principal sources of the blood supply. Microdissection and transclarification of Spalteholz allowed for the study of the direct and indirect arterial branches which form the principal network of the subcutaneous tissue. The findings are of practical importance since the subcutaneous tissue can be used as a separate flap for covering soft tissue defects of the forearm and hand.