A vintage textile label says rayon; an article about the same era discusses nylon. Both belong in the history of manufactured fibres, but the names are not interchangeable. Treating them as one material can blur the very development you want to understand.
Begin with the material description
McGill University’s explanation of rayon describes it as regenerated cellulose. That is a useful starting distinction from a vague label such as “old synthetic fabric”.
Keep the source’s material terminology beside the object’s actual label. If a garment has no reliable identification, do not assign a fibre merely because its date or shine looks familiar.
Compare questions, not impressions
Make a card with three fields: what the label states; what a reliable reference explains; what remains unknown about this object. A general history may explain a material without identifying a particular dress.
A fabric can also contain more than one fibre. Read the complete description instead of selecting the word that best fits the story you hoped to tell.
Follow a separate timeline
Build the history of each named material from checked sources. Keep invention, commercial production and the date of a specific object apart.
Our introduction to nylon’s development offers a separate trail. The point of comparison is to preserve meaningful differences, not to rank materials from appearance alone.