Bonus set to add to set B. Using set D, together with the templates of set B, you can make a lot of new blocks. The templates are made of the same acrylic material as quilt rulers, so they can be used with a rotary cutter. First, strips are cut of the right width, and then the templates are positioned on the strips, to make the second cut. Each template has double blunt corners for perfect alignment. The blocks go together past, easy and perfect! Set D has 8 parts, e.g. an isosceles triangle that fits in a 4inch square. You can now make star blocks with skinny point, or Attic Windows.
The book Encyclopedia of Patchwork Blocks part 2 contains a lot of blocks you can make with this set, in combination with set B.