5 CONCLUSIONS

Of the cotton unbleached backing fabrics studied, only for the warp sateen fabric were the face and back sides found to remove differing numbers of fibers, while for muslin, duck, and sailcloth the top and bottom sides of the fabrics were equally abrasive. Muslin was the lowest in abrasiveness as determined by the modified crockmeter test, while the other three backing fabrics removed more fibers. When fabric weight and weave construction were examined, the lightest weight fabric, muslin, was the least abrasive, while the heavier fabrics were more abrasive. However, the sailcloth was no more severe in removing fibers than the duck and sateen, even though the sailcloth was the heaviest. Weave construction and degree of yarn interlacement were evaluated. Unlike the original expectations, the satin weave, which had the fewest interlacements, was in the more abrasive grouping, while the plain weave with the most interlacements was in the less abrasive category. Thus, of the four fabrics tested, the lightweight muslin was the least abrasive in nature. The other three fabrics—duck, warp sateen, and sailcloth—appeared more abrasive, although they differed among themselves when weight and fabric construction/yarn interlacement were analyzed.

Testing of additional backing fabrics is planned in order to answer questions raised by this initial study. These questions include: What is the action of different fibers such as linen, silk, and synthetics, which are longer and smoother than the cotton fiber? What are the effects of the amount of yarn twist or various yarn sizes on the abrasive nature of the fabric?

It is acknowledged that the relationship of this abrasion test to actual textile mounting conditions has not been demonstrated. However, actual mount displays and conditions were observed, and similar conditions were selected when working out the testing procedure, e.g., the movement of one fabric surface against another. When the general requirements of a testing procedure are understood, then the real actions of movement and abrasion that may take place slowly over days, weeks, or months must necessarily be quickened. This abrasive test is fast and simple to perform, uses equipment that is not prohibitive in price, and provides a range of measureable values.

Although accelerated from actual museum conditions, this methodology appears to provide a procedure for measuring fiber loss due to abrasive action of fabric surfaces. It also allows comparison and rating of the backing fabrics tested and should help in providing a better understanding of certain important factors at work in such situations. Certainly, the abrasive action is only one of many factors to be considered when appropriate backing is selected. However, conservators who are concerned about fiber loss with fragile historic textiles may find this information useful in selecting less abrasive backing fabrics.