A couple of months ago I flew with someone who was using reusable sandwich bags in her lunch. I loved the idea and wanted to make some for myself and the boys. After googling the topic I found several posts and tutorials which invoked the question, "What fabrics are food safe?"
After reading way too many articles and blog posts with varying opinions on food safe fabrics, I decided to try using ripstop nylon for my lining and cotton for the outer layer. What I've read is that ripstop is especially safe if it's not coated, and if it is coated then be sure to put the coated side away from the food. I found this to work well and it was easily accessible at my local fabric store. The kids tested these for a couple of weeks and all of their food stayed fresh with the exception of the Pirate Booty which seemed to get stale after a few hours.
More recently I found another supposedly "food grade" fabric called ProCare which does not contain DEHP, Phlalates, or BPA plasticizers. I found a couple online sources for ProCare and decided to order mine from here. However it did take a good 2 weeks to arrive. The ProCare is definitely more waterproof than the ripstop, and I found it easy to sew as well. Until I find something better, ProCare and/or ripstop nylon will be my liner of choice for making reusable bags.
There are many choices out there. Some people even suggested sewing a Ziploc bag or cereal bag as a liner. Others suggested only using polyurethane coated nylon which I have yet to find a supplier for. The bottom line is to use what you are comfortable with and what works best for your family. Do the research and decide for yourself. I am not an expert but after all the reading about and testing of fabrics, I decided I was comfortable with the two fabrics I used.
In addition to finding many opinions on fabric choices, there were also several different ideas on how to sew the bags. I decided to go with this pattern. I really like the simplicity of it and also that there isn't any inside seams that food can get stuck in. I cut the fabric for the sandwich bags 7 1/2 x 15 inches and the snack bags 7 1/2 x 11 inches. I also chose to use Velcro on the tops because it keeps everything nicely tucked inside.
The bags are easy to clean. At the end of the day, I simply turn the bags inside out and rinse or if needed scrub with my kitchen soap/brush and set out to dry, and then at the end of the week I throw them in the wash.
I love these bags and so do the kids. They got to choose their fabric from my big bin of leftover fabrics so it was a win-win for all of us. The best thing is not having to buy and throw as many plastic baggies as we have in the past!