Originally printed using PLA filament.After printing, lay flat and gently push links together to break any filament.1/4X1/4 magnets required for included clasps. Make sure you put magnets in first to get the polarity correct before inserting clasp plugs. I used Lee Valley magnets, part number 99K3601.Support material only required on clasps as shown in picture.Link spacing is every 12mm if creating your own chain with your own clasps.Longer chains, with 23 or more links can only be printed on loger bed printers, or if you build a chain up yourself with angles or arcs.