I don't know about the Bank of Canada trying to save money by bypassing the lacquering of new CBN $5 notes. The median lifespan of a $5 note in circulation is 6 months, while the polymer notes are not due to be out for at least 18 months...
However, I think you're on to something regarding a fundamental difference between CBN and BAI upgraded $5 notes. The BAI notes have a thicker layer of lacquer BUT that layer does not cover 100% of the note surface. There is a lacquerless gutter (channel?) around the holographic strip on the face. If you hold a note up to light at an angle, you can see the differences in sheen around the strip which itself is covered with a polymer(?) layer. The gutter measures about 15-16 mm wide and varies in position around the holographic strip from one note to the next. The strip itself is 11 mm wide, so there's about 2.0 to 2.5 mm of gutter on each side of the strip. I tried to take a picture of the differences in sheen to show the gutter on a BAI $5 note. Here is the best I could do...
{http://www.give-a-buck.com/special/BAI-lacquer.jpg}
I compared this to a CBN $5 note, prefix HAB, and found the note has no gutter around the holographic strip. Just like its BAI counterparts, there is a protective coating on the strip itself, but no lacquerless zones around it. The HAB note feels less slick, but it doesn't feel dry like unprotected paper. I think there is a thinner coating of lacquer but that coating covers 100% of the note, meaning the holographic strip is printed over it.
Recalling that BAI started printing upgraded $5 notes without a thick lacquer coating in prefixes AOF and AOG, I pulled out my small stash of Unc AOF notes and had a closer look at them. There appears to be a gutter around the holographic strip, but the gutter is narrower, barely wider that the strip itself. Wish I could get a picture of this, but I don't have good enough equipment (or skills for that matter) to produce an image worthy of posting. So maybe it's kind of a misnomer to call the early BAI $5 notes "lacquerless". There just appears to be less of it on those early prefixes.
The differences between the CBN and BAI $5 notes presents a conundrum. Does this mean there are two suppliers of security paper supplying each company? Or is there one supplier making two kinds of paper? Or are the banknote printers applying lacquer coatings themselves? This deserves further investigation. I wish I could be of more help, but CBN $5 notes are still sparse in Eastern Ontario. They appear to be more abundant in Southern Ontario and on the west coast.
