I use them all the time. Not only are they priced reasonably for an envelope, but they are light enough not to increase your postage.
π Luxury Air Bubble Cushion Wrap Roll - Fuxury Bubble Roll
3 Review
π¦ 6X10 Inch Pouches for Secure Cushioning in Shipping Supplies
3 Review
Innovative Nifisa Honeycomb Alternative: Remarkable Cushioning for Ultimate Comfort
4 Review
Honeycomb Cushioning: Eco-Friendly Biodegradable & Recyclable Wrapping Solution
3 Review