This is the thread I will be using whenever I stitch with white in the 2021 Snowflake Sampler Block of the Month. Its size is perfect for this project, and it is a non-divisible thread. It has a slight sheen as opposed to white sashiko thread which is a matte finish.
Recommended needle size is 8 or 9 embroidery needle.
100% Cotton colorfast thread
87 yards of thread