Sashiko needles are extra hard and sharp. They come in several different lengths (e.g., the shorter ones from Clover you can buy here) for various types of sashiko stitching. The longest needles can take a little getting used to, but they are practical for long straight stitches because it's faster when you can load many layers of running stitches onto the needle before pulling the thread through. Sashiko stitching can also be curved and have many different patterns, in which case shorter needles are advisable.
A special thimble is used
The needle has a relatively large eye to accommodate sashiko thread, which is quite thick.
The needles measure 65mm and 48mm
Sashiko thread can be purchased here.
Instructions for sashiko will be available on this website eventually, but it will take some time. Many have requested sashiko supplies for a long time, so I'm choosing to sell them before I can provide instructions in Norwegian for those who want them.
Search for sashiko on YouTube, and you'll find a lot of good help! There are also dedicated sashiko groups on Facebook, for example, and several handicraft guilds offer sashiko courses, so check with a handicraft guild near you if you're interested!
The book Mending Matters also covers a lot of stitching inspired by Japanese handicraft techniques.