yep...if you are right about the question...then the actual length of the top and bobbin threads should be the same unless your tension is off or you are doing embroidery, then you would be using more top thread then bobbin thread as most embroidery machines adjust the top tension on the machine to pull more of the top thread to the bottom so as not to have the bobbin thread pokies showing on the embroidery. I suppose you would maybe want to do the same when thread painting....?????