100 Poly mailers with Flamingo 10x13 Flamingo Designer Poly Mailers Shipping Envelopes NEW Included 100 10" X 13 non-padded poly mailers. These are nice not only for those of you who sell on Poshmark and other places, but they're also great for mailing gifts. Ideal for your shipping. I have thank you label in my closets. PRICE IS FIRM Shipping Supplies, Great for shipping quality sealing so you can ship with confidence ! Thank you Cards, Stickers in my Home section.