Many thanks for your help dimkir
a) correct, using beziers, etc
b) correct. When the generation is complete
c) yes, my screen. The pdf now is created, completed, and close. For the next vector I will generate a new pdf file
d) yes, a new vector on the screen, the new vector will be recorded to a new pdf file.
So if I create 10 vectorial shapes, each shape gets recorded in one PDF file ending with 10 PDF files.
I want to avoid each vector to overlap by clearing the screen each time I generate a new vector.