It has been long known that any thread is influenced by the spindle whorl used as tool, by the fibre used as raw material and by the personal preferences of the spinner that is making the thread. How and to what extent each of these three factors figures in the look and feel of the finished thread is, however, not yet known. The experiment outlined here is designed to isolate each of the factors that influence the spinning process. By having a large enough group of proficient spinners process a given amount of different fibres on different spindles, it should be possible to isolate each of the influences through statistics and thus pinpoint the effect of fibre, spindle and spinner. With the data gained in that experiment, it might be possible to connect certain thread properties to spindle whorls from archaeological finds and thus to better evaluate the archaeological objects in future.
For the experiment, a large enough number of spinners is needed to get statistically significant results. Each of the spinners needs to be proficient enough to spin a smooth, even thread on a given spindle. The spinner has to be able to spin the thread in his or her preferred thickness and twist direction/twist tightness for at least an hour. Diameter and twist of the thread are not relevant, only evenness of the thread is necessary for the analysis. Since most spinners get to have a "personal preferred thickness" of thread after a while, finding enough persons competent enough should not prove too great a problem. For statistical significance, at least 20 spinners should participate.
The influences tested in the experiment are the weight of the spindle whorl, its moment of inertia, the fibre type, and the influence of the spinner. The spinner's influence on the thread can only be deduced after the other influences are known.
To test the influence of the spindle, different whorls are mounted on the same spindle stick. A copy of an archaeological spindle whorl will serve as the parent whorl. From this base, four other spindle whorls are developed: Two with the same moment of inertia, but a different weight, and two with the same weight, but a different moment of inertia. To test the influence of the fibres, two different types of wool will be spun on each spindle.
The full run thus consists of five different spindles - the parent spindle and the four modified spindles - that are used by each spinner to process a certain amount of each wool type. The fibres are prepared mechanically for maximum evenness to avoid any irregularities because of differring raw material. After completion of the spinning process with twenty spinners, there will be twenty examples of thread from the same fibre from each spindle. This should generate enough data from threads to separate the influences of spindle weight, spindle moment of inertia and fibre properties. The differences that are left will show the extent of the spinner's influence.