When I swap, I post the blocks that I plan to send in (unless it's a secret) both pieced and machine embroidery (usually an outline red/black work design rather than a dense fill in). If I see a block that I must have, I PM the hostess and beg. Same if I see something that I'd rather not have. "I'd prefer not to receive..." All the same, I have several swap blocks that don't agree with me, just waiting for the right project to keep, trade or give away. There's always something perfect for me or for someone else; machine embroidery being acceptable for the right project.