I designed my handmade toys to be as natural and as safe as possible which is why I use paper cord to thread my toys. It is rather durable and comes in different thicknesses plus it is completely safe for your birds to chew.
When I first got into birds I struggled finding affordable and safe toys for my birds. I only had Rosie (galah) and Tofu (lutino cockatiel) at the time. Tofu wouldn't touch anything I bought and Rosie only chewed soft materials. I could not find a variety of large soft material toys so I started making my own. I tried mahogany, palm and cork for the first time with my birds and they loved it! I would buy kabobs to thread these soft materials on them but I could not find many toys made of these materials which is why I started making my own to sell.
The links I sell are made from stainless steel which is completely bird safe and doesn't rust (if your birds fiddle with links too much I suggest using paper cord to attach them to your birds cage instead).
Description of materials:
Sola- Light and foamy like popcorn, the bark is thin, crispy and somewhat stringy
Mahogany- Solid and crumbly, dusty once chewed
Willow grass vine- Crispy and somewhat stringy
Balsa- Fibrous like wood, easy for small beaks to dint and chip away at, much much softer than pine
Cork- Rubber like, harder than mahogany to crumble
Pine- Rather hard but can be chipped away at, varies in harness, big chewers tend to like it
Palm- Stringy, chewy and crispy, fun to unweave
Abaca- Much tougher and thicker than palm