If you want to make a Boro cloth that resembles the authentic stitched Boro cloths of the past, this fabric stitched with the Olympus Sashiko thread,
MC-T6 INK BLACK sashiko patch boro mending collection - fabric
Cast Iron Black Cloth for Boro & Sashiko - A Threaded Needle
Boro Sashiko Fabric, Wallpaper and Home Decor
6 - 6x 8 sashiko designs printed on sakizomemomen (yarn dyed 100% cotton fabric) These are wonderful if you are looking for a traditional look
Sashiko Patch Mending Collection, Black
Fall in love with boro & sashiko stitching Combine hand stitches to create dramatic, unique designs and learn to embrace imperfection, admiring the utilitarian beauty of every stitch. Shibaguyz Shannon and Jason Mullett-Bowlsby invite you to try your hand at boro, the traditional Japanese art of mending and quilting, and more than 30 authentic sashiko designs. Stitching lessons are true to tradition, inspired by historical works by Japanese masters.
Boro & Sashiko, Harmonious Imperfection: The Art of Japanese Mending & Stitching [Book]
DIY: Sashiko Needlework Sampler Cloth — Loop of the Loom
Soot Black Cloth for Boro & Sashiko - A Threaded Needle
Boro Sashiko Fabric, Wallpaper and Home Decor
Boro Sashiko Fabric
A Word (or Two) About Boro and Sashiko - C&T Publishing
Soot Black Cloth for Boro & Sashiko - A Threaded Needle
Visible Mending
Sashiko Patch Mending Collection, Black - A Threaded Needle
Boro Sashiko Fabric, Wallpaper and Home Decor