the reproduction you use....is it 100% wool or is it a mixture like most "wool" blankets now adays.
Sold as 100% wool, and appears to be so. I also have a 1940s era Navy blanket that IS 100% wool that I use for "show."
Wool is best, but a small amounts of synthetics (maybe up to 10%) would not necessarily be bad as it would enhance durability.
I'm not an expert in weaving, but I'm told that often commercial and artistic weavers use jute or other natural materials as part of their warp and weave. It has to do with the stresses of weaving. If you want to know more then I'll have to send you to Google or Wikipedia.
I got two, from different periods. My ACW/IW era blanket comes from The Blockade Runner in Wartrace, TN Blockade Runner Civil War Sutler Sutlery 8-17-12
My modern era blanket comes from What Price Glory in CA What Price Glory
If you want a more colorful presentation go to a Pendelton Wool Outlet Store. They sell second quality wool blankets (the flaw is usually a minor weaving defect, color defect, minor handling damage, etc.). Seconds from Pendelton, a quality brand, are still of very high "operational" quality.
I would not use a 100% synthetic product unless it were specifically formulated for equine use.
The saddle blanket lives in a harsh environment (hot, wet, and constantly abraded and stressed by movement). Something from Walmart or Target likely won't do the job. Whether you go for wool, a blend, or a synthetic buy quality
. It won't cost; it will pay.