Well, they’re not really pattern bags but that’s what I use them for. I got mine in my local craft shop and they come in a range of sizes. The ones I’m using at the moment are A5 and 8″x 8″. I believe, in North America you can get a better version in the comic book store. The ones I have are used to put your pretty home made cards in to keep them nice to sell. I haven’t been able to find a 7″ x 7″ bag locally yet.
Me, I’ve been using them to put patterns in. Generally the A5 size is perfect for Simplicity but the larger sizes are good for indies, vogue and other big envelopes.
genius! I realise I am probably the last person ever to work this out but still! And another fantastic way to procrastinate!