Hello Niklas, It is not possible to pass the value of the plot (in your case a) by reference. When you declare b = a in our sample code, you are saying that b is equal to the handle that represents the plot within a. So changing the name of b is really changing the name of a because b has the same handle as a. If you run your code from IDL and look at the Variables tab, you will see that both a and b reference the same plot.

I found the solution and put it in a little function so everybody who might come accross the same question can use it: ;============================================== ; Function to copy Object Heap Variables FUNCTION CopyHeap,OBJECT temppath=FILEPATH("tempo",/TMP) tempvar=OBJECT SAVE,FILENAME=temppath,tempvar temporary=temporary(tempvar) RESTORE,temppath RETURN,tempvar END ;============================================== ; === example ==================================== a=plot([1,2,3],[42,42,42],/BUFFER,name="FIRST") b=copyheap(a) help,a,b ; this prints plots with different numbers and I think this function should work with any ObjHeapvariable