Linen stretched or Linen on board

First off I need to give a preface to this topic. I have read a book posted in my last blog "The Materials of the Artist" that talks about this topic. I have also talked with Robert Doak
who is a very knowledgeable man when it comes to oil painting. I have also talked with other artists about this subject and they understand (on a large part) very little about their tools they use on a daily basis. Which is kind of frustrating. I am very impressed with Adrian Gottlieb, and Kamille Corry because of their knowledge in the field of painting and their tools. So here is a breakdown with the pros and cons of each surface to paint on both being linen because it lasts longer and doesn't flex as much as cotton.
Stretched Linen:
Pro1: This is the main purpose of linen you pull it tight around stretchers, rabbit skin glue a couple of layers let it dry and it gets really tight like a drum. Then you paint oil primer on it (because acrylic is absorbent, kind of like traditional Gesso) and let it dry for a couple of weeks. Or if you are using preprimed linen like Claessen's then you just stretch it.

Con1: Once stretched their is no backing to protect the canvas, this can be fixed by placing some foamcore or Masonite (very heavy when dealing with larger art) on the back
Con2: Cost is relatively low because stretchers are not that expensive
Con3: The stretcher bars warp, even really expensive stretchers, the most successful stretchers I have used are backed with Aluminum but they cost a pretty penny.
Con4: You need to go beyond the painting surface to have enough fabric to stretch which in my eyes is wasteful.

Linen on Board:
Pro1: Uses less linen than stretching.
Pro2: Because the linen is attached to a board it has a backing and is less easily punctured.
Pro3: It is harder for moisture to get on the back of the Linen and damage it (we are talking over 100 yrs of moisture)

Con1: The proper way to mount linen is time consuming and you only have some much time to do it because of drying time with the Rabbit Skin Glue.
Con2: If you use wood like stretcher they do warp, a light weight alternative is plastic (which you need to make sure is PH balanced) , Dibond which is aluminum on front and back with a plastic substance in the middle (about $100 for a 4x8 ft sheet, it is used for outside billboards, it can be purchased at Regonal Supply located in SLC but Aluminum adsorbs temps easily so keep it out of the heat), Gator Foam is the most used now days. It is PH Balanced, very light weight, and doesn't warp easily.
Con3: If you have someone build it for you it will cost a good amount. A good company I recommend is New Traditional Art Panel located in Northern Utah. They make high quality panels with a removable backing.
Side note for panels:
There are three major ways to attach the linen to panels.

Traditionally: (found on pg 39 of "The Materials of the Artist") The linen must be sized a little larger than the surface to be mounted on about 1/2 inch in every direction. The linen is dipped in RS (Rabbit Skin) Glue (Robert Doak recommends after you have soaked the RS Granule for a half a day and then heated it, and never let it boil, you should place half the amount of Titanium White pigment in the RS as you did Granule, eg: 3 TBLS of RSG, add 1.5 TBLS of TW. It helps it dry faster and you can see that you have covered the entire surface). Lay the linen on the board and smooth it out from the middle to the edges, after 24 hrs of drying you can Prime it with Oil Primer.
This method is more permanent than some contemporary methods.
Contemporary method 1 Permanent: (from "Landscape Painting Inside & Out" by Kevin MacPherson) He and others use PVA Glue which is PH Balanced but once you have glued your linen down it is glued down. (Also PVA Glue gets brittle after a while and it does not flex with linen, which provides a struggle when one is applying force and another is not, but then again that might just be with canvas stretching and not mounting to a board) All you have to do is Place the glue on the back of the linen and the front of the board for a great bond. Then you smooth out bubble from the center moving out and let it dry. Problem is if the board gets damaged or warped it is really hard to take off, I would not recommend this approach and never use a glue that is not PH Balanced it will eat your expensive linen or discolor your painting.
Contemporary method 2 Non-Permanent: This one took me a while to find information on. New Tradition Panel's uses this method. They use a PH Glue called BEVA that when heated up (about 150 degrees ) the glue releases and you can attach the linen to a different board. This is a great option in case any damage is done to the painting or the board. You can buy BEVA as a toxic liquid (use a respirator) or a dry mount. Another less expensive PH Glue is called Versamount and you can buy some from http://www.framingsupplies.com/PrintMount/Versamount.htm This is a dry adhesive and you activate it by heating it up, I have used an iron to heat it up between the linen and board, be careful not to scorch the linen, that would be bad. Most businesses that use the dry mount use a Vacuum Heat Press which costs a couple thousand dollars, this is the best method to attach a non permanent linen to a board.
Summary: I prefer mounting to board, I already have a protective backing, I can remove the linen if it or the board get damaged or warped, and it is light. To me it takes less time than stretching. For bigger paintings I will stretch with a hybrid stretcher bar of wood an aluminum. Robert Doak, and Adrian Gottlieb (on his website) do not recommend using preprimed linen or priming your own linen then mounting it onto a board. They prefer the traditional method, but I have not received a straight answer on why I could not stretch and prime my own linen then adhere it to the board. My thoughts are once it is stretched and primed, I can adhere it to a board, the canvas wont flex or crack because it is glued to a board. But they recommend stretching unless you like the hard surface. I do agree with them on preprimed linen, it is not the highest quality, it is just easy to buy it all done so we can paint.
But this is the foundation we are talking about, if the foundation is not good then you are not going to get a long lasting painting. I trust my what I build to be of the highest quality, I will not take short cuts. How can you tell if you have a good foundation? Try lightly bending a corner of the canvas placing the canvas back to back, if it is built correctly it will flex, if it is crap the linen primer will crack or flake off. Also linen needs to have a strong tight weave, not a lot of holes. If it does have holes (empty spaces between linen weaves) then get a different linen. RSG is used to protect the canvas from the oil and fill tiny tiny holes between the weave, not fill large gaps, it will eventually crumble because it has only its self to adhere to.
Now that this topic is off my chest I feel better, I hope that it helps some of you artists out there. If you want to learn more read the books I recommended last week, it is amazing what I have learned out of school.