what's the difference between pbt and ABS?

The main differences between PBT (Polybutylene Terephthalate) and ABS (Acrylonitrile Butadiene Styrene) keycaps are based on their material properties, durability, texture, and manufacturing processes.

1. Material Properties:
   - PBT has a semi-crystalline structure that makes it stronger, more heat-resistant, and generally more durable than ABS^[3]. In contrast, ABS is more flexible and easier to mold, which contributes to its widespread use in mass-produced keyboards^[6].

2. Durability:
   - PBT is more resistant to oils and chemicals, which prevents it from developing the greasy appearance common with ABS keycaps^[3]. ABS keycaps, while cheaper, can wear down more quickly, with issues like faded legends and a shiny look due to prolonged use^[1].

3. Texture and Sound:
   - PBT keycaps typically have a matte, textured feel and produce a crisper sound when typing^[1][6]. ABS keycaps, on the other hand, have a smooth, shiny texture that can become slippery and develop a worn appearance over time^[6].

4. Manufacturing:
   - The production of PBT keycaps is more complex and costly due to the material's properties, leading to fewer options available in the market compared to ABS^[5][6]. ABS keycaps can be produced in a wider variety of designs and colors, partly because the manufacturing processes are less demanding^[5].

5. Cost:
   - Generally, PBT keycaps are more expensive than ABS keycaps, reflecting their higher durability and quality^[6]. However, some high-end ABS keycaps can be quite expensive as well^[6].

In summary, while PBT keycaps are tougher and offer better longevity, ABS keycaps are often cheaper and more readily available, making them a common choice for many users. Ultimately, the choice between the two comes down to personal preference and specific needs.