Well, it's been a while since I purchased any - last I bought was probably from Yoav, ArtisanGeek, who I don't believe is still in business (?). It may be that it was rectangular, and I just cut it into squares. But in any case, it was still quite wide. I think my squares are around 24" on a side, something like that. That is more than enough to fill the mold and have plenty overflowing on all sides. If yours is too narrow to overflow on all sides, I think it is going to be very challenging to get it pulled smooth.