#10 Regular Envelopes-Business Envelopes White-24Lb 4-1/8 x 9-1/2 Inch- (55/pack) #10 Blank Regular envelopes are ideal for most business documents sent daily to customers and vendors such as letters, invoices, statements and much more. These are standard 24 lb. white stock with Moisture activated gummed seal and measures 4 1/8" x 9 . Commercial flap envelope 55 pack