Right now when we go out, my daughter (5 weeks) wears wool covers over cotton diapers. What might I do when summer comes? I don't want to use synthetics.
At home the cotton diaper is sufficient, and if my EC technique improves we may not use those much either when warm weather comes. But I do have a worry about leaking while at somebody else's house or around town.
If you want to avoid synthetics you're probably going to need to stick with wool covers. Are you using longies now?
You can get wool wrap covers that are cut just like the synthetic covers. Imse Vimse makes good ones, and you can also find some that are made by work-at-home moms. BioBottoms makes a line of really pretty wool covers and has several different cuts available.
A light wool wrap cover will cover only the diaper area. Wool is also a breathable fabric that will allow air circulation.
Wool covers are also extremely durable and will last to be passed on to many babies.
Outside of a trim wool wrap you're going to find synthetic materials, even if they don't touch the baby. All organic cotton covers have a laminate to make the waterproof/water resistant. Sometimes this layer is sandwiched between other layers, but it's still there.
I would opt for bare bottom, or just the cloth diaper at home and reserve a lightweight wool wrap for when “out and about.”