#10 Regular Envelope - 24# ReEntry Red (4 1/8 x 9 1/2) - Astrobright Color Series (Box of 1000) A Quantity of 1000 - #10 Astrobright Re-Entry Red Envelope Made with 24# Astrobright ReEntry Red Paper. FSC Certified. - Regular Gummed Flap Great for mailing letters, invoices, statements, checks, certificates, contracts, and more. This envelope may be sourced from any one of a number of top brands. Ships via UPS Ground