A recent question on a society heraldry Facebook group about the dimensions of the escutcheon on the submission forms reminded me that I never posted the comparison outline I put together last year showing how it diverges from the geometric construction typically used to create this “heater shield” shape.
The most common technique for drawing a heraldic escutcheon, shown in red below, is to lay out a rectangle which is three times as wide as it is tall, then add a pair of quarter circles below it, enclosing the area where they overlap.
The escutcheon on the society’s submission forms, shown in black below, is slightly different; the curve starts lower and then pinches in more steeply.
I don’t know if there’s a concrete reason these curves are different; it may have been an accident, or an aesthetic judgement by the illustrator, or perhaps there’s some other explanation that’s been lost in the mists of time.
The difference is relatively small, but it’s enough to bite you if you use a computer to create field divisions or peripheral ordinaries or the like. Submissions which do not use the precise escutcheon shape from the form are likely to be rejected.
I haven’t found a geometric construction that precisely matches the submission form, but I’ve very carefully traced the outline from the form so that I can create heraldic clip art that matches it.
For the curious, the whitespace inside the escutcheon is a couple of hundredths of an inch over 5″ wide, and a couple of hundredths of an inch less than 6″ tall. After adding a two-point outline (2/72″) around the edge, the solid black outline is 5.06″ x 6.06″.
The diagram above is available as a PDF; you’re welcome to print it out and hold it up behind a copy of the submission form to confirm that the outlines match up precisely.
Folks who are creating digital submissions might be able to save some time by reusing the outline I’ve traced, either with the alignment tick marks (SVG vector, 300 DPI PNG) or without them (SVG vector, 300 DPI PNG).
As I remember from my analytical geometry class from high school the submission escutcheon, or Tudor Escutcheon, is drawn from a french curve overlay of a parabola based upon either the 3rd or 4th prime. Unfortunately, have neither my class notes, nor a perfect memory of 50 year old seminars and lectures.
That would be fascinating if true, but at first glance the curve does not look particularly parabolic…