I have just found a blog, Sri Threads, with some wonderful examples of sashiko to enjoy. Some of the images loaded a little slowly (or it might be me!) but they were well worth waiting for. I think I need to make a nice cup of tea and sit down with my laptop and go back into the blog archives to view such delights as a sashiko stitched noragi stitching over shibori There are some very utilitarian examples - which is what sashiko was in the beginning after all - and some very intricate, decorative pieces of work, all a joy to behold and a source of infinite inspiration.
Oh my goodness, I've just been clicking around and found that Sri sells things! Go and have a look at their website , as well as books and textiles to buy there is a wealth of background information on Japan and Japanese textiles. Enjoy!