Kamon, Japanese (family) crests are a wonderful design resource that I have used a lot for sashiko. I wrote an earlier blog post about them here, but since then I've taken many more photos of kamon on trips back to Japan, so here are a few. The one above, from a temple in Kyoto, is a variation on the tomoe comma kamon, with four commas, while the one below has three. The simplified triple version of mitsu tomoe is one of the crests included on my 2019 sashiko kamon panel for Olympus Thread Mfg. Co.
This lovely antique tsutsugaki (rice paste resist) furoshiki wrapping cloth from my friend Chie Ikeda's collection has a triple ivy leaf kamon, the same one I have on an antique sashiko furoshiki, surrounded by the takarazakushi or collection of treasures motifs.
this blog post). This noren door curtain is from that house.