Pyramid or "silken" bags are environmentally bad. They are made from plastic or nylon and are not compostable or biodegradable. They aren't microwave safe.
Ancient Forest Black Tea, Pyramid Tea Bags
PG Tips in hot water as drinkers say their eco-friendly pyramid tea bags break apart in cuppas
Can You Reuse Your Tea Bags? Yes! Here's How
Easy Ways to Avoid 3 Chemicals That Make Your Tea Toxic - TEATIME NOTES
The Advantages of Pyramid-Shaped Tea Bags: Enhancing Your Tea Experience – Japanese Green Tea Co.
The Pros and Cons of Loose-leaf vs Tea Bags
10 Plastic-Free Tea Bags For Steeping Sustainability
The Dangers Of Microplastics In Tea Bags – Wise Ape
Which tea bags are free of plastic? - SCUBA News
Pyramid Tea Bags Release Billions of MicroPlastic In Your Tea