Here are some factors that could be considered in evaluating the authenticity of your violin:
1. Provenance: The history and ownership of the violin, known as its provenance, is an important factor. If there is well-documented ownership history connecting your violin to the Stradivari family or reputable musicians or collectors, this could support its authenticity.
2. Physical characteristics: An authentic Stradivarius violin should display specific physical characteristics, such as precise craftsmanship, the choice of wood, the varnish, and the scroll design. These features are often meticulously examined by experts.
3. Handwritten label: While some Stradivarius violins may have handwritten labels, others may have printed or inked labels. The presence of a printed or inked label does not necessarily mean that the violin is not genuine.
4. Expert assessment: The most accurate way to determine the authenticity of a Stradivarius violin is through an examination by a qualified violin expert or a reputable appraiser who specializes in string instruments. They can assess various factors, including the construction, materials, craftsmanship, and other indicators of authenticity.
5. Family history: The fact that the violin has been in your family for at least 100 years is certainly notable, but it does not conclusively establish its authenticity.
It is important to remember that there are skilled artisans who can create replica or imitation Stradivarius violins of high quality. Therefore, a thorough evaluation by an expert is crucial in making an accurate determination.
If you believe you have an authentic Stradivarius violin, it is advisable to consult with a professional violin appraiser or an expert in stringed instruments to conduct a detailed examination and provide you with a reliable assessment.