A
stain on a garment will make you
niddah only if it is larger than a
k'gris, the size of a US dime or Israeli shekel.
When a stain is found on a garment that is partially white and partially colored, only the white area on the garment is counted towards a
k'gris. Therefore, if a stain is found on the white stitching, as long as the total area of the stained white stitching is less than a
k'gris, it may be disregarded. This is true even if the entire stain is visibly larger than a
k'gris.
Please feel free to get back to us with any further questions.
B'Hatzlacha!
