When dimensioned isometrics are plotted, all dimensions are rounded up or down to the nearest mm or 1/16 inch, depending on the current output units. By default, ISODRAFT carries over any remainder (positive or negative) from a rounded dimension and adds it to the adjacent dimension. This process minimises cumulative errors over a number of consecutive dimensions, but it can result in identical fittings being shown with different lengths (usually differing by 1mm or 1/16 inch).