It maybe that a master signing a work was simply making a declaration that the work met the standards of the shop.
And it wasn’t just painters. Sculptors also worked together.
In fact, assistants were even more necessary if you were a master sculptor because statues take longer to make than paintings.
And the master had to arrange for marble to be quarried, things like that.
Perhaps the most collaborative of all was architecture.
There we see a real division of labor, but with carpenters, masons, unskilled labor just to carry materials to and fro, and so on.
Plus, of course, your skilled artisans who carried out the master architect’s design.
Think of it, like, um, a ballet, you know. All the dancers work together.
There’s a division of labor. People have different roles.
And in order for the thing to come together, everyone needs to be aware of what others are doing and coordinate their work and have good timing.
So for architecture, it’s almost impossible to know who was responsible for any given detail.
Was it the master architect? The mason? An assistant mason?
Maybe it was even the patron, the client who was paying for the art.
Remember, it wasn’t yet customary for architects to give their assistants measured drawings to work from.
Instructions were given orally, not in writing.
So we don’t have those documents to tell us what exactly the master architect’s plans were.