How to export Art brushes as vector NOT bitmap?

[Helle]

Yes, it is made of more than one vector shape (see image) Nothing fancy, simple lines in different tones....
Can you tell me what format I have to export as for other vector programs to treat is as vector. I think I have tried many different methods. Tried to "convert to editable shape", "convert line to shape" etc. but nothing seems to work correct! Maybe there is a trick I don't know, please :-)