Pratt MJ-4 Self-Seal Stay Flat Mailer, White, 9.75" x 12 1/4" (Pack of 100) (2-(Pack))

I am very pleased with these! I bought them to mail some 9 by 12 inch prints that I made. They fit the paper size well. They were sturdy enough to protect my prints with breaking or tearing. When I mailed them at the Post Office the clerk asked if it was OK that they go through regular mail (where the machines would bend them up to a 45 degree angle). [If you want to send them through USPS with something that should not be bent, you would just have to pay a dollar more per envelope to get them manual process and therefore skip the machines.] I took the gamble and said yes to the regular processing. Even so, they still arrived in good condition! I have not gotten any reports of damaged prints.

As a first-time Etsy seller, I was nervous about all of it and trying to find the best shipment supplies to protect my products (within my budget). That said, I did a lot of research. I have only used a few of these so far, but I am impressed. They aren't rock solid firm or anything—they do bend a bit—but customers have all reported their success in keeping items safe and sound.I've been shipping art prints that are also wrapped in clear cello bags, for reference.

I use these for sending out a 28-page hardcover children's book I wrote, illustrated, and released in April. It measures 8x8 and fits snugly in the flat mailer, but I made sure to leave a little over half an inch of space all around to allow the book to be easily removed from the mailer as well. The thickness of the mailer itself is what made me opt for this version. Despite my packages being tossed around in the back of trucks and into bins, etc., they can take the wear and tear, and books are delivered with no damage, which is what you want. I tested these myself and have verified with far off customers who have received them with no problems. Worth the buy!

All in all a good "fairly" rigid mailer. They aren't as rigid as what I've seen from Uline, but with shipping, the mailers from Uline are more expensive as well. To reinforce, I use corrugated or chipboard inserts. The adhesive is good but when the mailer is stuffed, I do see the adhesive give up a bit towards the edges of the mailer.

I ship art in these and go through thousands of these a year, they are fairly rigid, but I still use chipboard inserts to add sturdiness, the sticky strip on these is great, dont expect to be able to open these babys up again without pulliing the release tab, just what i need for my day to day photo/art shipping

Very happy I found these mailers! A great bargain and high quality! Was spending far more for another brand, which was equating to a lower profit margin for my small business. With these mailers, I’m able to keep more of my profit on each product I sell.

Exactly what I needed. I ship tons of vinyl decals, and this makes the process painless. No need for any chipboard or anything to stiffen it up. Just slide in the decal and instructions, seal, put the shipping label on, and drop it off. I save money in shipping supplies and save tons of time, resulting in faster turnaround on getting orders out.

Excellent deal, and good products. These are quite solid, I would not hesitate to ship art or other valuable 1-page items without additional cardboard backing. I also use to send rare comics and paperback books - for these I do add chipboard backing to be extra careful. But I think these are thick enough envelopes the items could ship with no additional support.