Hi @toto, do you mean that the circle edges are pixelated ie. there is no antialiasing?
If so you may be interested in the issue I created today on psychopy’s github page:
I’ve managed to solve that issue by creating the window object with different parameters (see the issue above, the solution was suggested here) - this can not be done in the Builder directly unfortunatelly (AFAIK). But you could add a code component that replaces automatic builder window with a custom one. Let me know if you need help with that.