LUX Monarch Envelopes (3 7/8 x 7 1/2) in 24lb. Bright White are perfect for the Holidays/Invitations/Announcements/Sending Cards, sold as 250 per box..Comes in 24lb. Bright White.Sold as 250 per box.Dimensions: 3.875"L x 7.5"W.LUX Monarch Envelopes (3 7/8 x 7 1/2) in 24lb. Bright White are perfect for the Holidays, Invitations, Announcements, Sending Cards, and so much more!.Appropriate for everyday business correspondence and home office use, the Monarch envelope (3-7/8 x 7-1/2) is an attractive solution for your stationery needs. Available in the same size as our 7-3/4 envelope, the Monarch is distinguished by a longer, triangular flap. While the Monarch is a reasonably-priced envelope suitable for frequent usage, the bright-white looking stock looks like youve spent much more on this affordable envelope. Available in White only.