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Adjustable Saddle Pads Shim

What is ThinLine?

ThinLine is a thin, shock absorbing non slip breathable foam.

Where is the ThinLine?

It is sewn onto the panel of our saddle pads. Here you can see the ThinLine foam on top of a western cotton liner pad. 

endurance round skirt saddle fit pad


Click to view more saddle pads

Saddle fitting solutions are easy and with ThinLine saddle fit inserts

you will double your results by saddle fitting with the best therapeutic materials.








  • High Withers: Add Front shims to any pad.
  • Hollow or Sway  Backs: Add bridging shims.
  • Rider Balance: Adding a pair of shims to one side can fix balance issues.
  • Saddle Balance: Front or rear Shims, depending on your issue.
  • Saddle Slippage: Generally no shims are needed, the ThinLine Pad alone will solve this.
  • Saddle Pad Slippage: Generally your tree is too wide. Add a Booster Shim.
  • Equine or Rider Back Soreness: No shims needed, ThinLine protects both.
  • Equine Asymmetry: place both of the pair of shims on the hollow side.
  • Kissing Spine Relief: Add a Booster Shim to any ThinLine pad.
  • Treeless Saddle Pad Comfort: Add a Booster Shim to any ThinLine Pad.

Photo: Front, Bridging and Rear Saddle Fit Shims and the Full Booster Shim.

Stacking and layering saddle fitting shims.

  • ThinLine pads accept up to three 1/4 inch saddle fit shims in a single location.
  • 1/4 inch front, bridging and rear shims are the most popular but you can also purchase a thinner 3/16″ shim for bridging issues or to fill behind wide shoulders.
  • Layering sets of shims will create an even transition for major saddle fit issues. Shims may also be cut with a pair of scissors for custom work.
  • Full booster shims are 3/16 inch thin, when placed under the panel of ThinLine already on your pad you have now generated 1/4 inch of ThinLine protection.
custom saddle fit shims inserts
Layering sets of shims

How to order Saddle Fitting Shims.

Select a ThinLine Saddle Pad.  Once the pad is in your shopping cart, scroll down and you will see a product called “Add Saddle Fitting Shims To The Pad In My Cart”, simply add the shims you need.

Click here for Western Pads

Click here for English Pads 

Click here for Endurance and Treeless Pads

OR Click Here to view Saddle Fittings Shims for our most popular pads.


Image: Booster Shim Inserted into Pad

The entire area under the ThinLine portion accepts up to 3 sets of 1/4 inch shims in one area. There are no “pockets”, allowing you to place stack and create gradual transitions between shims.

Saddle fitting with this with shock absorbing foam provides balance, comfort and protection for horse and rider.   Now you simply need to find the pad that fits the dimensions of your saddle and the style that fits your life.  Read on if you need more detailed saddle fitting information.

 Adjustable Saddle Pad Shims

ThinLine, with or without shims, protects horses and creates saddle fit. For balance or to adjust hard to fit horses our pads have a full open pocket, allowing you to place the Therapeutic Shims exactly where you need them.


Master Saddlers and ThinLine developed a shimming system designed to create custom saddle fit while also providing shock absorbing therapeutic benefits. ThinLine saddle fitting shims are made from the same trademark foam found on ThinLine pads. In addition, shims are easily inserted or removed and stay in place during riding and washing. 

Now adjusting your saddle also provides more ThinLine comfort. 

Saddle Fit Problems Solved: High Withers, Bridging, Asymmetry, Soreness.



Easily resolve saddle fit issues for horses with hollow or sway back, high withers, saddle balance, mutton withers (rolling saddles), asymmetrical fit, or sore backs.






felt barrel saddle fit pad

The full, open panel allows you to place shims exactly where you need them.  Use up to three pairs of 1/4 inch shims in the same location at once.


Popular Saddle Pad Selections:

Trifecta Half Pad
High Wither Contour Ranch Pad
Endurance Drop Rig Pad
Full Sheepskin Square Cotton Dressage Pad
Dressage full sheepskin
Saddle Seat Equitation Pad






Underneath the ThinLine layer is a pocket to insert shims. If you need help with minor saddle fit adjustments, purchase your saddle pad and use it alone or add shims. Either way, your saddle will fit better and your horse will use his back better and stay sounder longer.  Shims are made of the same therapeutic ThinLine material. Once you place a Thinline saddle pad in your shopping cart you will see below your cart, Add shims to the pad in my cart. Simply add the shims you need.

or read on to learn more:


What is ThinLine? ThinLine is a shock absorbing foam which delivers protection for both horses and riders.custom saddle fit shims inserts

The only product endorsed by surgeons, master saddlers & veterinarians. 

 What makes ThinLine so different?


“The manner in which this product absorbs motion encourages horses to lift their backs, developing strength and top-line.  It has been endorsed by Veterinarians, as well as Spinal Surgeons for Riders. It is a top pick for Master Saddlers around the world, Equine Chiropractors and Massage Therapists carry it on their trucks to keep horses going strong, supple and relaxed.  Because ThinLine is dedicated to the comfort and health of horses we even work with other Therapeutic Companies such as Back On Track; where they incorporate ThinLine into their designs.”

It is the dual benefits of extraordinary shock absorption and motion reduction that really sets ThinLine apart from other saddle pads.


What is ThinLine? ThinLine is a unique, open-cell foam which moves shock, weight, and heat laterally along the pad without compressing. The result is 95% shock absorption.  But don’t let all the testing and technology get in the way of what really happens; extraneous motion and impact is nearly eliminated, leading to comfort and a quiet connection for both parties.  All this is delivered in a breathable product measuring only 3/16 of an inch (4.6mm) in thickness.

Every Saddle Pad comes with this extraordinary technology.  English and Western saddle pads also come with a pocket to add saddle fitting shims, also made of the same shock absorbing foam. Nonslip and breathable.

Technology For Riders:

ThinLine moves impact laterally instead of up into the rider’s spine.  Thus reducing back strain, providing wear and tear protection for riders’ spines while improving equitation and delivering a close contact feel.

Spinal Surgeons research saddle pads and endorse ThinLine
Improved equitation and shock absorption in an Ultra ThinLine Pad is quite measurable.


          The ONLY Saddle Pad Endorsed by Spinal Surgeons:testing sensors


Technology For Horses:

SMS master saddle fitters Master Saddlers research ThinLine. 

So many horses improve top-line muscle tone by using ThinLine Master Saddlers such as Cordia Person (CSF) who also educates saddle fitters on how to shim with ThinLine. Custom saddles, fitters like Cordia, recommend Basic ThinLine Pads to protect backs and keep saddles fitting until the next check.  ThinLine will not alter the fit of custom saddles.


Popular Saddle Pad Selections:

Trifecta Half Pad
High Wither Contour Ranch Pad
Endurance Drop Rig Pad
Full Sheepskin Square Cotton Dressage Pad
Dressage full sheepskin
Saddle Seat Equitation Pad





Adjustable Saddle Pad Shims

Click Here to Purchase in the USA 

Click Here to purchase in EU and UK