Collectability Corner: Old Plastic and New Plastic Stablemates

 We're back in the collectability corner! Today I'll be talking about the difference between old plastic and new plastic Stablemates. 

When the Stablemate line was first introduced in 1975, they were molded out of cellulose acetate like the larger scale models. Around 1992, the plastic was switched to polystyrene. From that point, all Stablemates were molded in the "new plastic," though there have been some exceptions. The 1998 JAH set debuting the G2 molds, the Stablemate Club models, and the Vintage Club stablemates have all been molded in the old plastic. 

The easiest ways to tell the difference between the two plastics are what I call the tap test and the clunk test. The tap test is performed by tapping the leg of a Stablemate with your fingernail. The new plastic has a much tinnier, high pitched sound when tapped compared to the old plastic. Ditto the clunk test - set a Stablemate down on a hard surface like a table. Old plastic Stablemates will have more of a thunk compared to the lighter new plastic. I've posted a reel about this to my model horse Instagram. 

Another important thing to note about the new plastic - it absolutely cannot be exposed to the sun. Polystyrene yellows in sunlight. And some late 90s and early 2000s Stablemates will have plastic discoloration regardless - the blog Many Mini Hooves has a wonderful post about the yellowing found in this period of production. At this time, there is no known fix for yellowing of new plastic Stablemates. Old plastic Stablemates on the other hand can be safely whitened in the sun. 

A selection of the original Stablemates line from the 70s. All of these models will be old plastic. 

I didn't think I had an example of the changeover in plastic in my collection, but it turns out I did! This is #5025 Running Thoroughbred, produced from 1991-1994. The model on the left with the completely black hooves is old plastic, while his companion on the right is new plastic.

Here you can see the size difference that sometimes occurs between the two plastics. Again, the old plastic model is on the left, the new plastic model on the right. In general, new plastic models can be slightly larger than old plastic models. I have also considered the possibility that my old plastic model is a shrinky, as he is from that time frame, but he doesn't exhibit any signs besides being smaller than his new plastic double. 

A selection of models from the 1992 Sears/1994 JCPenney Holiday Catalog set that I have in my collection. These would be some of the earliest models produced solely in the new plastic. 

I haven't tracked down all the models in this set yet, but here are some representatives from the 1998 JAH set. This set debuted the new G2 molds, and was entirely produced in old plastic. 

An example of yellowing that can naturally occur in new plastic Stablemates from the 90s. A significant portion of this run goes yellow. The white example on the far right is my newest acquisition from October. He is the whitest example I've found. This picture makes the yellowed ones look better than they are - in person they are bright yellow. 

Another view of my yellowed Native Dancers. You can see how the concentration of the yellowing varies from model to model. 

The inaugural run of the Stablemates Club - this club advertised use of the old plastic as a selling point when launching the club. The Vintage Club also uses old plastic for their Stablemate releases, both the yearly bonuses and the five piece optional purchase released last year. 

Two modern Appaloosa Silky Sullivans! The stars of my Instagram reel demonstrating the difference in the plastics, we have a new plastic model on the left (#10306 Hidalgo Buffalo Bill Playset, one of the last appearances of Silky Sullivan before the license with H-R expired) and an old plastic model on the right (#B-CS-10351 Spencer, a release from the 2025 Stablemates Club). 

A molding irregularity that can occur with modern old plastic models - they occasionally end up looking pinched. On the right we have Klaus, a 2020 Stablemates Club release. On the left is Darwin, the original mold release for the 2018 Premier Collection. You can see how Klaus is significantly narrower behind his shoulders than Darwin. The Stablemates Club Valerio has the same issue in the neck. 

An unfortunate victim of the sun. This new plastic G2 TB mare somehow ended up in view of the sun while in my horse room and it turned her one side completely yellow. Like with the Native Dancers above, she looks much worse in person. She's shown here with an old plastic Arabian Mare for color comparison. 

My poor Orkney from BreyerFest 2020. He has gone completely yellow in the time I've owned him with just his tail tip showing the color he used to be. His neighbors on the shelf were completely fine, so I don't think he received sun exposure, and he's pretty uniformly yellow. In trying to find a replacement, I've noticed several of the run have also gone yellow, as have a handful of Jerseys and Skyes from the same BreyerFest. Unfortunately, there's nothing I can do for this poor fellow. 

So, to recap the differences between old plastic and new plastic: 

Old Plastic

• Cellulose acetate, like what the big Breyers are made from
• Used on Stablemates models produced from 1975-1991
• Additionally used for the 1998 JAH Set, the Vintage Club Stablemates, and the Stablemates Club releases 
• Heavy, makes a fuller sound when tapped and a thunk when sat down 
• Can be whitened in the sun 

New Plastic

• Polystyrene
• Used on all Stablemates models from 1992 onward
• Lighter, sounds more brittle and tinny when tapped or set down 
• Cannot be whitened in the sun - the sun makes these models yellow faster