Prestige Saddle Tree Width

I just got a new horse (16.1h OTTB) who is still filling out muscle/topline-wise. I need to change the tree on my Prestige (34, widened to a 36 for my lease horse) to fit him better. Obviously saddle fitting/custom saddle is in his future once he has filled out, but this is for the time being while he is still developing. My best guess is he’ll need a medium tree once he’s filled out.

(Going from Warmblood X’s to OTTBs is hard- I’m used to just buying the largest size in everything!)

What’s the best “general” size tree for a Prestige for an average build horse? Do I go back to the 34 or see if it can be narrowed to a 33?

When I bought my Prestige earlier this year the saddle fitter told me that a 34 was an average size and would fit the most horses. He did mention though that it could be narrowed down to a 32 to fit a super narrow horse (possibly like your TB?). Is it possible to have the person who will be adjusting the saddle come out to measure, or can you do your own tracings to send to the fitter so you get the best fit possible?

I have a Prestige size 34 and a horse size 33 that is still to full out. The saddlefitter told me I can co down one size by using Mattes saddle pad made od thick sheepskin.