packaging packaging paper office school a7 plain mouth black envelope 100 pack

in people's daily lives, envelopes are an information bag device used for mailing letters and preserving their contents. they are generally made into rectangular paper bags. envelopes can be used to send good wishes to customers on their birthdays and holidays, which is also a good way for customers to increase their stickiness to the enterprise. enterprise envelope printing, as a promotional method for the enterprise..syi