Paul your shop shouldn't need to draw a line on your cam for timing because most BowTech's come with the timing mark's anyway's ,you may not see them but if you use the light they'll be there .

As for Parker they need to sharpen their skill's and be able to answer these kind of question's because somewhere along the line ,I'm sure they've been asked before ,Why should a string maker have to guess .It's either black or white none of this grey..

nubo