I call this knot the Rose. You can find my inspiration on folio 33r of the Book of Kells.
Back in my pencil and pen days I wanted to use this element as a major component in a large piece I was creating. My reference image was from Bernard Meehan's "The Book of Kells" book – the photo was full page and pretty clear, but the knot itself only about 1.5cm across.
For over a week I worked back and forth between Meehan's book and my sketchbook with magnifying glass, pencil, ruler, and (mostly) eraser before transferring it to the final page and inking it. You can see a scan from that point in the process in the centre of the image above.
The completed piece was a gift that, unfortunately, was not appreciated, and for a long time I baulked at the thought of doing anything more with any part of it. They say it’s not a total waste of time if you learn something from it: I am now far more discerning about who I build bespoke art for...
...Eventually I reclaimed the rose. In 2013 I started digitising key elements of my original pieces, and made a first pass on the rose, straightening and balancing the lines. Then, in mid-2018 l decided to use it in our signature block. While no knot is ever perfect, I felt it was worth investing another couple of days in tweaking and tidying it a little more, then made another version modified to fit better into a circle.
You can find the rose in the background of every signature block from our 2018 work. That block will be retired at the end of the year, but I'm sure the rose will make plenty more appearances.
[ Post Script... While writing, I looked back at folio 33r. Much more accessible now thanks to Trinity College Dublin's digital collection! On reflection, I see that the horizontal and vertical lines aren't really meant to be so straight: I've lost the swirl and flow of the original! So I'm going to need to loop back on the rose in 2019! ]