Sharpe points out that at Heathrow Airport in London, for example, you may bring aboard up to 2 liters each of baby food and milk as long as it’s stored in a clear, transparent container or bag.

On the (nerve-wracking) day of travel, I hooked it around my stroller handles and was impressed with how light (just under five pounds!) and flat it was—comparable to a long folder (17.7" x 14.6").