I think I read somewhere ("Increase Essentials"?) that the cloth or silt liner wicks away moisture/condensation. I guess with a cloth inner, any condensation would not be as apt to form droplets and rain back down on the cluster. I was at an apiary south of STL that used cloth, and each cloth "inner" had a small flap cut which could be folded back to allow bees access to a feeder if necessary. I liked it, and may try it out.
This past Winter we were given the choice to adopt a huge collection of brand new linens (mostly towels --> wash clothes) from the estate of a recently deceased relative. So we had all of our older linens available to use them to see how old terry cloth towels suited for use as "inner covers".
I installed some on my nucs, but soon discovered that during our cold Winter nights they trapped too much moisture inside the nucs, causing moisture problems.
Now that Summer is here I have tried using them again and find that they work much better at this time of year.
I know of only one person who uses cloth "inner covers", besides me. I inherited them from my friend when I got some of his covers. He uses plywood migratory covers, as do I, w/ a hole in them for a feeder pail to sit above when feeding. He uses canvas from Army tents from the Army Surplus Store. When he doesn't have enuf of that material available he uses tar paper.
Mostly it closes the hole when not feeding. But it also makes a tighter seal around the edges under the cover then does the plywood.
SHB and ants love to congregate under the canvas, and especially the tar paper, on top of the top bars. Rip it off quickly and you might have a chance of hive tool testing some of those buggers.
A forum community dedicated to beekeeping, bee owners and enthusiasts. Come join the discussion about breeding, honey production, health, behavior, hives, housing, adopting, care, classifieds, and more!