I agree.... This may be true with AOG as both AOF and AOG were with-held for about 6 months after the release of the varnish 2006 $5 Notes....
I still firmly believe this is DIRECTLY linked to the BoC analyzing the results of the Varnish vs Non-Varnish.
So lets say the old notes had a lifespan of about 12 months (Some say 9 Months but lets go with an even year). So then if the varnish is designed for 18 months they should cut down costs by roughly 50% (Better quality...Less Printed).....
So then they release the Varnish notes (We saw AOH to even AOR right off the bat), 6 months before the rest and then they can compare the quality of the notes at the same time and determine of the added cost is worth it before expanding it to other denominations (I think $20 Notes would be the next candidate myself).
When CBN was printing notes it cost the BoC approx $0.02 per note but with BAI Printing these notes with the varnish and such it costs them about $0.12 per note (Also for better Quality/Error Free notes).
So this is a SIGNIFICANT investment the BoC has made into this technology. Will it be worth it? I don;t think we will know until Summer of 2008 when the changeover happens (At the soonest). That leaves a few month to make a decision and then go either way for the next Print order.
BoC orders 4 times a year from the printers. So in reality the printers are printing Canadian Notes for short periods during the year. Notes are stockpiled and distributed as required.
I feel the First order of notes might have been small (AOF & AOG.... Might have even been made at the same time as a CBN order of 2002 Notes to have time to work with the notes... Makes sense since it is IDENTICAL paper to the 2002 Series). They pulled them aside (They took their time printing them to ensure quality and give confidence to the BoC and win the contract for exclusive printing of 2006 Notes.)
Then the next full order was AOH - AOR
Then following that was AOS -
(Current) and then when we see the changeover that SHOULD signal the start of the next order that was made.
This is just my opinion but it makes perfect business sense.
Now as for AOF Bricks. I have had a few (And the lowest serials seen BY FAR). I never found ANYTHING other then poor quality notes (BUT ERROR FREE!!!). They had Lots of ripples generally.
I never got any AOG Bricks... so I am unable to speak for them. Being that NO REPLACEMENTS have been found in the prefix does lead to some suspicion as to WHEN the notes were printed in relation to the Varnish notes..... Possibly quite earlier.... and were completely separated on purpose.
If no varnish notes were printed at the time there would have been nothing to replace with. It would also look bad if they had replacements going that quickly as well.