Egenberg, I. M. & Moe, D.: A "stop-press" announcement. Damage caused by a widely used herbarium mounting technique. -Taxon 40: 601-604. 1991. -ISSN 0040-0262.The storage conditions in 4 Scandinavian herbaria have been checked, including indoors climate, mounting techniques, paper qualities etc. Serious damage to plant specimens glued to standard herbarium sheets has been found, while specimens mounted by traditional paper strips were unaffected by changing temperature and relative humidity.In Spring 1990 four herbaria, BG (University of Bergen, Norway), C (University of Copenhagen, Denmark), TRDH (University of Trondheim, Norway), and TROM (University of Tromse, Norway) were selected for a check of storage conditions, and paper, label and glue qualities used in the routine mounting processes. The work was the basis of a thesis by the first author at Konservatorskolen (Det Kongelige Danske Kunstakademi), in Copenhagen (Egenberg, 1990).The report of the project demonstrated clearly that controls and some improvements were needed in all herbaria . For some improvements, more money is necessary, but for others, only small changes in the routine work, with a minimum of cost, will suffice.Storage conditions like controlled temperature (between 13°and 18°C as an optimum: see e.g, Franks, 1965;Staniforth, 1986;Bottomley, 1986)and humidity (between 45070 and 60 %: see e.g. Staniforth, 1986; Ausland, 1986); reduced UV radiation by the use of suitable light bulbs or filters (maximum 75 lux or lower: see e.g. Egenberg, 1990;Staniforth, 1986); and minimized dust, are always important for all museums. Standard recommendations exist for art museums, which can be adapted and should be followed (international and national references include e.g. Thompson, 1986;Anonymous, 1980).In most cases art galleries and art museums are, so far, more aware of these problems than herbaria.Paper and label quality were checked for all herbaria. Within each herbarium a wide range of paper quality was found, from rather acid (pH 4.9) and bleached to more acceptable, non-bleached, with a pH close to neutral (maximum found: pH 7.9), and with a good fibre standard. As for storage conditions, herbaria can use the recommendations followed by art galleries and most art museums. Paper acidity must be higher than pH 5.1 for the sheets used in Norwegian herbaria.Special attention was given to the different mounting procedures used (see e.g.
