These pre printed panels from Olympus Thread Mfg. Co. are called 'hana fukin' with literally means 'flower cloth'. They are printed in grey on indigo blue coloured narrow width traditional sarashi cloth (an easy to stitch traditional Japanese cotton cloth). Each panel is supplied in one piece with a plain area the same size attached, because they are designed to be stitched through both layers and the edges turned in to make a little cloth, but you can stitch the printed layer separately (as I often do).

'Fundo tsunagi' means linked scale weights and is a similar pattern to the apple core patchwork pattern.  Stitching guide included, in Japanese, but with easy to follow diagrams.
 
Sarashi cloth is quite lightweight compared with other sashiko fabrics, but is very easy to stitch, super absorbent and wears well.  It is one of the fabrics traditionally used for kimono underwear!
 
Finished size approx 13in (33cm) square.

Marks wash out. NB - the marks have less contrast than my pre printed sashiko panels. The fabric is indigo colour, not natural indigo, so the colour won't run.

Designed and made by Olympus Thread Mfg. Co.in Japan.
 
100% cotton.