I'm a fan of Epic fabric and have used a Western Mountaineering Ultralight in conjunction with a Bibler Winter Bivy for many years now in all seasons and have never really had an issue with breathability. So when I got my FF Vario – 1/2 bag thing (more like a 3/4 thing for me) I chose the Epic cover option and have been really satisfied while using the Vario WITHOUT a bivy. However, I'm wondering if condensation will become a much greater issue in warmer temps (above or near freezing) if I use the Vario with my Winter Bivy or Integral Designs S. Col EVent Bivy.
I've used the Vario many a time with my EVent bivy, and had no issues, but it's always been in winter conditions.
Thoughts on Epic sleepingbag shells with Epic bivy sacks?
I'm thinking about packing my Winter Bivy – or "Bibler's Summer Bivy" as Ryan would prefer – while tarp camping to provide a little more foul weather protection without adding the weight of my full EVent Bivy.
