(Can't read the damn paper, even with University journal access. Why is academia so fundamentally stupid? Is it not obvious to a scientist that when your paper comes out it would be a good idea for a lot of people to be able to read it?

Thanks to Cell Press for extracting profit to hold back scientific progress.)

Anyway I presume this relates to the group's previous work, where they boil the wood in sodium hydroxide to leach the lignin and then compress it. The final product doesn't have any resin additives, so is not a composite.