Well Libby, you certainly have a eye for detail . and at 17 the worlds your oyster, hope you have every success in the future.As for the headaches my 21yr old son use to suffer for days on end, mainly after a intense sketching session (must be a arty thing) the hospital put it down to too much concentration whilst painting/sketching ect. let us know how things go..i might have a beautifull little spar i need you to draw for me .