What a wonderful horse. Hubby bought a handful of 5′ plastic “noodles” often used as pool flotations [Wiki]. Ours are a rainbow of neon colors for eventual use in ground exercises, for example, asking him to walk through an arch with noodles.
The plan for the day was to bring the noodles into the field, catch Rodney, put on the Halter of Doom, bring him over, see how he felt about them. Never got to the halter. As soon as I dropped the pile in the field, up went the ears, and over he came to check the novel things out. Sniff this one. Sniff that one. Oh, look there’s more. Graze.
Initially, he wasn’t thrilled to have them moving toward him, but he expressed reservation more than hysteria. Within 10 minutes, I was comfortably tapping him all over with a noodle. I even rested one on his back. Fortunately, it didn’t fall off. I wasn’t ready to test the system that far. Mind you, this was al fresco. He could have run off at any point. I can think of a lot of horses who would have.
What an inexplicable horse. Leather halter? Eeek. Shiny, weird, plastic, scary things? Meh.
Virtual Brush Box 
So? That’s easy – a plastic halter. You can knit or crochet one from plastic grocery bags. I saw a purse yesterday in black (large garbage bags) and a white and red tweed-like color (Target). Was’t as bad as it sounds. The bags are cut into strips and then knit/crocheted as usual.
Which color did he like best?
Halter needs at least one breakaway &/or leather piece for safety. Otherwise, his color is green.