There used to be a setting for this (labelSize), but that one only takes numbers for a fixed label size now as opposed to a string specifying how it should respond to zoom levels. Someone else also had this problem here (Sigma.js v2 Label Size proportional like v1) and was told that this was achievable with this custom label renderer: https://github.com/medialab/ipysigma/blob/master/src/custom-label.ts

Yet when I use this custom renderer the label size is still fixed and not proportional to the zoom level. Is there something I am doing wrong?

Many thanks.

I used this custom renderer https://github.com/medialab/ipysigma/blob/master/src/custom-label.ts and let my sigma instance use it (could confirm that it is actually using the custom renderer). Expected label sizes to be proportional to zoom level. Found them to still be static.