Siikala interview is very good.
It's good to see him also promise some "concrete" projects like 'zines!
Mentioned GRUNT / SIIKALA split LP-painting is currently in pressing. I suspect there will be some sort of full introduction of this project when first pieces of concrete samples emerge. It will be quite unique project indeed..
Man has been pretty much only guy I have regularly used for cover artworks on my different labels. It is because he doesn't have gimmick style. Especially many who do covers for metal bands, repeat the same dull elements forever. Many who developed their own niche, can not adjust to needs of bands or label. It seems very unusual situation to be man with vision combined to ability to be "craftsman" one can hire. Of course it is also good that he has not taken role of being "album cover artist" so it's not very common to see his works at this point.