With the growing number of people interested in instrument-making and in playing historic instruments, we find more and more people wanting to study these instruments. Museums and private collections sometimes allow interested parties to study them but more often than not access is very limited in order to better preserve the artefacts. One strategy for allowing access to the information is to make a detailed study of the instrument and to record the level of detail desired by the most demanding user (usually the instrument restorer or maker). The nature of a musical instrument, the hygroscopic wooden structure and the effect of the tension of the strings make this task more complicated than examining a static object. Very old instruments have often undergone restorations or repairs and these interventions must be recorded as posterior to the date of construction. This paper will propose a method and tools to document these instruments. This is an extensive set of guidelines which will help scholars to standardise this complicated task. The method described uses relatively simple tools but it should be noted that much more sophisticated techniques are being borrowed from other fields. A detailed examination of an instrument can help in its identification, aid in teaching lutherie, facilitate an appraisal, or simply record the condition of an instrument as part of cataloguing it. Another important use for this documentation is for making an authentic reproduction of the instrument which can then be played allowing the original to be preserved in optimum conditions.