Assuming the two spots are on a white cloth surface (and not on your body), each spot is assessed independently. The gris is a measure of area, roughly the same area as an American dime or Israeli shekel. If each spot is totally covered by such a coin, it is clearly smaller than a gris.

Since the measure is one of area, if the stain extends beyond the coin but does not fill it (i.e., it is long and thin or uneven), you could trace its shape onto a piece of paper, cut out the tracing, and then cut it up and rearrange the pieces to see if the area clearly fits within the area of the coin. If you are still not sure, or if the result is borderline, you should bring it to a rav for evaluation.

Please get back to us with any further questions.