shoresigns
New Member
FYI this method only works if you're measuring the last few feet of the roll. It does not scale all the way from an empty roll to a full roll of material.More like 10.2" per wrap assuming the outer diameter is 3.25". The number of wraps is ~= the thickness of the media and the backer * the total thickness of the media on the roll.* 10.2
The result will be slightly shorter than the actual length.
No, you don't need any kind of complicated math to calculate it fairly precisely.To compute the length precisely involves a bit of calculus which most likely is beyond then ken of the average sign maker.
You just average the inner and outer diameter of the material and multiply by pi to get the average circumference of the material, then you multiply that by how many times the material is wrapped around the core, which you can easily calculate by halving the difference between the outer and inner diameter, then dividing by the caliper thickness of the material.
That's how my spreadsheet does it, and I assume it's how the Avery and Signcraft calculators work, as they all generate the exact same results.