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.
Refreshing Mint Infusion Buy Eco-friendly Pyramid Biodegradable
The Best Plastic-Free & Compostable Tea Bags
Introducing JusTea's New Compostable, Zero-Waste, Plastic-Free Tea Bag – JUSTEA
Microplastics in Tea Bags: Is There Plastic in your Tea? - Organic India
Next Generation Non-GMO Pyramidal Tea Bag – Fraser Tea
PG Tips has reduced the amount of tea in its tea bags – still fancy a brew?, Tea
Next Generation Non-GMO Pyramidal Tea Bag – Fraser Tea
The Advantages of Pyramid-Shaped Tea Bags: Enhancing Your Tea Experience – Japanese Green Tea Co.
Why is Tea Bag Bad? Here are 4 Top Reasons You Should Know! – Cspuerh (Chen Sheng Hao)
What are the strongest tea bags? - Quora
The Dangers Of Microplastics In Tea Bags – Wise Ape
Sustainable Sipping: Dilmah South Africa's Biodegradable Pyramid Tea B
Pyramid tea bags better than round, advertising watchdog rules
JQ Jiaogulan Herb Tea Loose Leaf Healthy Gynostemma Tea Natural Sweet Stemless Caffeine Free 30 Pyramid Bags
Is There Plastic in Your Tea?, Treading My Own Path