Fits 4-Up Horizontal W2 Forms – Designed for blank W2 forms in a 4-up horizontal layout, compatible with QuickBooks and other common tax software. Pre-Aligned Dual Windows – Double window placement lines up with recipient and return addresses—no formatting adjustments needed. Privacy You Can Trust – Black security tint keeps personal and financial information fully concealed in the mail. Peel & Seal for Speed – Quickly seal each envelope without tape, glue, or moisture thanks to the strong self-adhesive flap. Clean, Durable Construction – Made with 24 lb white wove paper for a crisp, professional look and dependable mailing. Mail your 2025 W2 tax forms with ease using these Blue Summit Supplies envelopes made to fit blank 4-up horizontal W2 forms. This 25-pack is fully compatible with forms printed from QuickBooks and other leading tax software, offering precise double window alignment for recipient and return addresses while protecting all other details. Each envelope includes a peel & seal flap for fast closure and features a black security tint to guard sensitive information. Crafted from 24 lb white wove paper, these envelopes are built for reliability and a clean, professional presentation. Note: These envelopes are specifically designed for 4-up horizontal W2 forms and are not compatible with 3-up, 2-up, or 1099 formats.