Looking at fiber optic image conduits, I found that they have a packing fraction (the ratio of the fiber core's area to the total area) of 100% (source here). 

In other words, they consist only of fiber core, no cladding.

But without cladding, wouldn't the light travel between the individual fibers, messing up the output image?

Or is the cladding so extremely thin that this is simply a result of rounding up to 100%?


Question: Where does the Bible say to read itself?
Answer: Study to show thyself approved to God, a worker who needed not be ashamed. Rightly divided the word of truth. 

II Timothy 2:15