Talk:French curve

why is it called french curve?
anyone knows why is it called french curve?

So far no luck finding out, there's scant info on the web; they are also known as Irregular curves and seem derived from Ship's curves, which date to at least the 17th century. So far the earliest mention of French Curves I've found is from 1817 in a list of drafting instruments in an estate sale. Msandersen (talk) 17:45, 22 June 2016 (UTC)


 * Been putzing around the net trying to find out more, and the closest theory (unsupported) is that they are called that because of the country they were largely produced in at the time, France, according to some answers on http://www.mapleprimes.com/questions/102902-Origin-Of-The-French-Curve-Or-Mathematical. However, not 100% sure.  32.212.104.223 (talk) 17:02, 24 May 2017 (UTC)

practical usage
How about a section describing their practical usage - something I have wondered about since I first saw one (about 40 years ago). In this article there is a reference to the idea of placing the FC on a surface so that it 'touches' 3 or 4 marked points - and I didn't even know that much. Even though I took a drafting course, the French Curve in our geometry sets were never needed. All lines were straight or circular - as is the case for most basic drafting. — Preceding unsigned comment added by 69.26.79.137 (talk) 13:50, 21 October 2012 (UTC)


 * French curves are used in drafting clothing patterns, like for neck and arm holes. 24.17.203.4 (talk) 21:31, 22 November 2012 (UTC)


 * On http://classroom.synonym.com/use-french-curves-8096234.html?ref=Track2 there is some example uses, for clothing and car design, stated. 32.212.104.223 (talk) 15:22, 24 May 2017 (UTC)

Speaking as someone who spent 25 years hovering over a drawing board as a civil / structural technician, I was told that the French popularized the standard patterns we used. In map making there are numerous instances of curve plotting and the finished work was always presented in ink. Freehand work was limited to hatchures representing slope and a few minor items. There are also German curves, as the article indicates. In addition, there are Danish Curves used in ship drafting and these are still used by model makers. I began my career nearly 20 years before computers and so learned all the old ways, which are not necessarily obsolete as the article states. — Preceding unsigned comment added by 24.89.18.210 (talk) 18:18, 20 March 2022 (UTC)

So, how come there rarely/never seems to be any markings on these things, like linear (cm/inch) distance along the edge, or indications of key points like the left-right transition on an S-curve? I'd think this is pretty essential when re-creating a curve with any degree of precision (like making its mirror image or reproducing it at a different scale), for instance in aircraft design etc. — Preceding unsigned comment added by 2001:2020:432B:F9F9:6C84:B46C:90FB:8D82 (talk) 07:20, 1 July 2023 (UTC)

add pictures
Please add pictures, including a combination french curve / protractor (which was standard plastic version in US schools in the 1960s).-71.174.183.177 (talk) 00:48, 9 April 2015 (UTC)


 * Pictures were on the page when I viewed it at 11:24 EDT 5-24-2017. But this was more a comment on the combination you mentioned.  I went through school in the 70s and 80s, and I don't ever remember seeing a combination french curve/protractor set up like you are describing.  They were always separate items for me.  The only thing tying them together was more often than not, they were made from the same color plastic.  32.212.104.223 (talk) 15:25, 24 May 2017 (UTC)

The pictures shown are German curves, not French. A full set of French curves have rather different patterns. The set of three are not necessarily used to plot the curves described, as ellipses are often drawn as an approximation composed of four circular arcs. — Preceding unsigned comment added by 24.89.18.210 (talk) 18:29, 20 March 2022 (UTC)

Technical information
Hello. It would be nice if somebody knowledgeable could add a few notes about the specifics of French curves, how they work, how they were developed and how they can be used.

For example, I recently saw a video called MIT Science Reporter EDM from 1962 showing early computer design software and comparing it to French curves. An equation was given for various drafting tools, such as the triangle being x=ay, the compass being X²+y²=r² and a longer equation for french curves. I would be very interested to learn about how these equations function with the traditional real-world french curve template for example.

Lots to be said about french curves!

Sam, UK — Preceding unsigned comment added by 78.148.188.126 (talk) 05:43, 12 June 2015 (UTC)


 * Only covers a part of your request for further information, but see my post above in "practical usage". Link posted to an article that at least answers the purpose (some) of these devices.  Possibly the idea behind the creation of them, if that is the purpose of the picture of the roadway.  32.212.104.223 (talk) 15:27, 24 May 2017 (UTC)

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Some computer-graphics systems
I have to take issue with ‘some’ here. I'd say almost all at this point, it's even been a standard feature in Paint since forever, so in the most rudimentary graphics program thinkable. And software that doesn't support Bézier curves tends to support something similarly powerful anyway. — Preceding unsigned comment added by 77.61.180.106 (talk) 22:42, 10 March 2021 (UTC)