According to Ribeiro, 1983 even if these paintings were accurately dated, they took many years for completion and underwent many alterations over the years.
Surviving garments are a major source to study the 18th century dress. They give almost all the information needed to study a dress like the cut, construction and adaptions through the century, stitching, embroidery techniques and patterns, richness of the fabrics, dying techniques, color and textile (Susan North, Welters and Lillethun, 2011). Some of the surviving garments also carried the names of the dressmaker (Rothstein, 1999). The only disadvantage of the surviving garments would be that most of the surviving garments are damaged and thus revived over the years loosing their original form, thus the information collected is not accurate as mentioned by Christman-Campbell in Welters and Lillethun (2011).
According to Chrisman-Campbell (Welters and Lillethun, 2011), fashion magazines were first seen in the 18th century. Magazines and publication were another sources, which gave information about the dress and the latest fashion not only in France but also around the world. There were also books, encyclopedias and dictionaries published that analyzed dress, how costumes were worn, terminology, movements, changes in fashion, etc. Points that could limit our knowledge in reference to this source would be that they were not very useful unless supported by other sources as there might be many differences like the interpretation of color might not be the same due the use of different dyes in printing or the authors might make their own interpretations of the dress. .
Fashion plates were illustrations demonstrating the highlights dress that were in fashion. They were not depictions of specific people but gave a generalized portrait of the ongoing fashion. As mention in Rothstein (1999), fashion plates in France had started being published only in the 18th century.