There is really only one part of the process of making a stained glass window that I really dislike. I think most stained glass artists would tell you they dislike the puttying part of the job. And while it’s definitely not the most fun, I turn on my music and just get on with it. The part that really stresses me is getting the measurements right. If the window is a rectangle it isn’t really a problem; though I can tell you that most window openings are not square. When it is a problem is when the window is a circle or has an arch. Then getting the measurements right is really critical.
For an arched window, the first thing I do is make a template of the opening. I take a roll of paper, place it over the opening, and trace the outline. Then I spray mount the tracing onto cardboard which I cut out and check against the opening. This usually requires several trips up and down the ladder to make adjustments to the fit. When I’m done, I have a template of the opening.
But to get the glass pattern size right I have to adjust the template. I have to subtract 1/8 inch for the hardware that holds the window in place, ¼ inch for the lead came border, and a 1/16 inch for allowance. Sounds pretty straight forward, right? Well if you are a numbers person, it probably isn’t a big deal. And even though I did well in math, it does not come naturally to me.
Because I am paranoid about this part of the process, once I have the final design drawn I adjust the template to the new measurements and make another trip to the client’s house to make sure I’ve got it right. So far, I have never had a window that hasn’t fit on installation day. Maybe after I’ve done a hundred or so of these windows, I’ll worry less. Until then, the extra trip to size the template is worth the peace of mind knowing that installation day will be a breeze.