Please bear with the grammarI use 3 different methods (one is yours Gary, modified though)
1) For Discover Fresco Workshops for Children introductory classes, presentations and "sample playing" 12X12 and 16X16 inch tiles are the most convenient for the following reasons:
a) Super Light (in fresco reference)
b) Enables you to go straight to the painting without missing much of the plaster part (most of it is "unconsumable" for the spectators, novice and kids anyway)
c) Gives an opportunity to walk virtually anybody through the steps of fresco painting without boring them to death.
setback - looks too easy.
8 parts sand 5 lime
2) For 2-day professional workshops and small frescoes I have adopted a modification of Gary's original method (details in student's forum) it really speeds up things since I need four panels for each student (do not worry, Gary, you get credit at every class).
This is perhaps a better choice for the museum - (I hope you will mention Gary and TrueFresco.com during the presentation)
3) For advanced Fresco Workshops and portable exhibition size frescoes, I use metal frames with earthquake resistant fastening system of my design the plastering methods are the same as above - they did it this way (plaster) for thousands of years and I do not see the reason to change.
About delamination - after 10+ years of my own and Ian's experiments and discussions/consultations with pro plasterers and especially after a few of the plasterers have attended my workshops and being third and forth generation plasterers had to straggle with the high calcium mortar (only thanks to Ian, he is an old English trained plasterer, they did not tell me to "go jump in the lake" before we understood the problem). I have come to a conclusion that the main reason for that is improper moisture control, wet mixes, thicker "topper" coats, faded knowledge of high calcium lime mortars and... (Gary, I am already ducking...) love of cement.
(more in student's forum)
lastly - the wall is plastered in the same way.
I know, Gary, we can not all "wear the same shoes" and perhaps your way could be much more outdoor resistant.
(Nathan & Gary, check your private message inboxes for my message)