These #10 security envelopes are a reliable and versatile choice for all your mailing needs. Measuring 4 1/8" x 9 1/2", they are perfect for sending invoices, checks, letters, gift cards, and more. Crafted from durable 20lb white paper, these envelopes feature a windowless design ideal for printing, labeling, or hand-addressing—making them perfect for bulk business mailings. The interior security tint protects sensitive information from view, ensuring privacy during transit. A convenient self-seal closure eliminates the need for licking or tape—just peel and press for a strong, secure seal every time.