sketch- how to change eraser size and be able to copy and paste with the knife optioin

[ohad alb 0]

sketch- how to change eraser size and be able  to copy and paste with the knife optioin?

this is very important ability and i saw in the internet that is supposed to be able however i am not success

 

[PinkElephant 8,114]

Eraser size: It always has the same size on the screen. But if you change the zoom factor, it becomes larger or smaller relative to the drawing. So Zoom in for more finesse of work, zoom out for erasing larger areas.

No luck with copy & paste - maybe you post your YT source here, and we all learn a new trick.