Description

These #10 Western Sulphite® side seam window envelopes measure 4-1/8" x 9-1/2" and are made from 24 lb white sulphite paper with a professional vellum finish. Designed for invoices, statements, checks, billing notices, business correspondence, and daily office mailings, these commercial window envelopes feature a poly “H” window for clear address visibility.

Key Product Details

Envelope Style: #10 side seam commercial window envelope
Size: 4-1/8" x 9-1/2"
Color: White
Material: 24 lb white sulphite paper
Finish: Vellum finish with 92% brightness
Window: Poly “H” window
Window Size: 1-3/8" x 4-1/2"
Window Position: 7/8" from left, 5/8" from bottom
Seal: Traditional remoistening seal
Seams: Two side seams under
Flap: Flap down
Certification: SFI Certified
Quantity: 500 envelopes per box
Manufacturer Item Number: 3103

#10 Side Seam Window Envelopes for Business Mailings

Western Sulphite® #10 side seam window envelopes are a dependable choice for offices, accounting departments, billing departments, medical offices, legal firms, schools, municipalities, and other organizations that send professional window mail. The 4-1/8" x 9-1/2" size is a standard business envelope format for mailing letter-size documents folded into thirds.

Each envelope is manufactured with two side seams under, a poly window, a flap-down closure, and a traditional remoistening seal. The “H” window is positioned for address visibility, helping streamline mailing preparation when documents are printed with the address already aligned.

Printer Compatibility Note: Not recommended for laser printing. Heat from laser printers may cause the poly window to shrink, warp, or distort.

Item Number	3103 / W3103
Envelope Size	4-1/8" x 9-1/2"
Paper / Material	24 lb white sulphite paper
Color / Finish	White, vellum finish, 92% brightness
Window Details	Poly “H” window, 1-3/8" x 4-1/2", positioned 7/8" from left and 5/8" from bottom
Envelope Style	#10 side seam commercial window envelope
Seal / Construction	Remoistening seal, two side seams under, flap down
Certification	SFI Certified
Quantity	500 envelopes per box / 2,500 per carton

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