Simply peel off the release strip and press! With clean seal envelopes, you will your mailing tasks done quickly and easily. Clean Seal envelopes form a secure seal quickly, with no moisture required. Open-end design allows quick and easy filling. Pack of 25 envelopes. Simply peel off the release strip and press Clean Seal envelopes form a secure seal quickly, with no moisture required. Open-end design allows quick and easy filling. Pack of 25 envelopes. The convenient pack size is ideal for small mailings.