Interconnects: solid or hollow core wire?

I just swapped out some unmatched stranded everything (off to my vintage cable museum!) for newer A'quest balanced and single ended ICs, solid core digital (coax) and solid core speaker. Nothing particularly pricey, and I did keep one old stranded Straightwire IC for a headphone amp because it looks cool (so sue me..it's blue with groovy plugs). There is some synergy there now and somehow solid core makes sense to my addled brain. I think the electrons are happy and moving along properly and my system sounds better...the major "skin effect" issue I have now is attended to by my dermatologist.

For the money, if anyone knows of a better deal than Mapleshade I am all ears!

Mapleshade seems too obscure to find at a discount (used or demo) so I think A'quest (for solid core anyway) is a better deal if you are patient enough to wait and not pay retail. For example, I found some clean Diamondback balanced ICs for $65 a pair. Hard to beat.

cogan hall, years ago manufactured hollow core interconnects. in the recent past, legenburg manufactured hollow core cables. both companies are no longer viable.

if by chance there exists a company which designs and manufacturers hollow core cable, listen to them and compare them to your favorite solid core cable. there are several types of solid core cable, including, rectangular solid core, cylindrical or circular solid core and ribbon cable.

So who all makes solid core interconnects?