Global Schwalm Sampler – Update (2) I have received a couple of requests for clarification regarding the edges of the contribution piece. So, there are probably others who have the same question. I hope the following is helpful. The piece should have a generous border of plain fabric all around – minimum 2cm as previously told – and straight cut edges. This means no hem or edge finishing (e.g. serged or zigzagged edges) at all – there must be enough plain fabric to be able to join all the pieces together.