All ancient frames were handcrafted, no machinery was used at all. In the 19th century industrial revolution was in full swing and most things that were handcrafted were now made by machines, this included picture frames, however the artistic work of the craftsmen never lost its significance. All frames handcrafted from previous eras had their own unique design inspired by furniture, this is how you could tell when they were made and something that even today exists.
The framing business and industry was taken to the next level during the 19th century as trading between countries enabled designs to be inspired by other cultures and new materials used to make the frames, also other techniques were learned and the addition of glass was introduced.
Picture frames began to be seen as a form of decoration, they started to be used in places of worship and homes to display artwork and cherished moments, they became a form of status, if you owned a picture frame, especially a more elaborate design you were seen as upper class or rich.