When choosing a string of additions in mind that the filling of the cell is not proportional to the number of additions. Or in other words, a cross with 2 additions will more effect (more filling) than the five additions to the half-cross.
The efficiency of half of the cross falls with decreasing numbers of the canvas (increase in cell size). But on the canvas with the number 16 and above is better to embroider, for example, addition of 2 ... 3 polukrestom than 1 ... 2 addition of the cross as if filling a similar need to embroider a factor of 2 smaller.
When you specify a melange yarn ispolzuktsya 2 additions.