Aluminium honeycomb - nortd/lasersaur GitHub Wiki
- either aluminium honeycomb slices (compressed) or uncompressed
- http://www.corex-honeycomb.com/aluminium-honeycomb.aspx
- expander http://www.coretexgroup.co.uk/resources/Coretex+Aluminium+Honeycomb+Expander+Datasheet.pdf
- EU aluminium honeycomb slices (compressed, reasonable price): http://easycomposites.co.uk/Category/Core-Materials/Aluminium-Honeycomb.aspx (see http://easycomposites.co.uk/products/core-materials/19mm-aluminium-honeycomb.aspx for a description of how to expand the compressed honeycomb)
- EU expanded http://plascore.com (high shipping costs to further away places)