Alfabatik Insulated Overbag - INFO Page

The Alfabatik line of synthetic insulated overbags are designed specifically as a cold season companion for quilts and mummy bags.

They provide a temperature boost of approximately 5-8 degrees while keeping most dew and mist from penetrating to the inner quilt

Having a quick drying synthetic insulated layer towards the outside will significantly assist in moving moisture away from the down filled inner bag/quilt (not included!)

Polartec Alpha is an ultralight fleece style knit with an open, mesh-like appearance. For our application we cover it with ripstop nylon

2 Models to choose from:

Original Hood-less Alfabatik

The simplicity of the Alfabatik full bag design, minus hood, eliminates the drafts and complex strap systems often encumbering the layering of synthetic quilts on top of a down sleeping bag/quilt. In extreme cold a quick setup of one's sleep system can be crucial; the over-bag concept facilitates this. 

The Polartec Alpha is an ultralight fleece style knit with an open, mesh-like appearance. It is a stand alone product that is covered on the outside with fabric to make this bag. 

For this we use a 7d nylon ripstop with a 'hot cire" treatment, resulting in a windproof, water resistant performance, with long lasting properties. This low-permeability shell is crucial for heat retention and as a barrier against outside moisture infiltration. Some condensation can occur between the Alpha and the HC shell, away from the underlying down bag/quilt. 

Additionally there's a very breathable, but not so weather resistant ripstop nylon for a slightly lighter, less warm bag with reduced condensation risk.

Or one can configure the Alfabatik Hood-less with the water resistant, low breathability fabric on one side and the more breathable one on the other, allowing the user to choose which type to face up depending on conditions.

The Alfabatik is a zipperless and hoodless bag with a drawstring controlled top opening and a sealed mummy style foot box.

Zippered Mummy Alfabatik 

This is designed specifically as a draft stopping cold season companion for quilts and hood-less mummy bags.

The popular down quilts are primarily applied for fair weather 2 season use. Used together with this fully enclosed mummy style overbag most 30°F and 20°F quilts can get an extended comfort range into the colder season via the many benetfits: Draft control from bottom and head opening, moisture control, temperature boost.

The mummy shaped design with a close fitting, draw string controlled hood just large enough to fit some UL pillow types minimizes drafts from the neck and bottom opening of quilts

It also provides a temperature boost of approximately 5-8 degrees while keeping most dew and mist from penetrating the to the inner quilt

Advantage of the Alfabatik Mummy overbag over a typical single layer DWR 'bivy': Alpha Direct insulation controls moisture and condensation from touching skin and quilt surfaces. Breathing inside the bag is less of a clammy affair. Shaped and tailored fit limits cold air traps and effectively controls typical quilt drafts from movement and wind. Sleeping pad do not go inside

Too snug for big winter mummy bags - see instead the OG Hood-less Alfabatik 

General advantages to using Alpha over the more traditional Climashield Apex insulator:

- Very low bulk. Foldable and compact in the pack.

- High resistance to compression damage from repeated stuffing and unstuffing. High loft Apex could be no warmer than Alpha after hard use.

- Can be slept on with limited risk of loft damage.

- Good long term durability compared to Apex.

- With the Alpha exposed to the inside of the bag it is simple to monitor moisture content and long term degradation.

- Like any woven or knitted material the appearance is consistent and even, unlike Apex which varies from wafer thin to full thickness from yard to yard.

- The low bulk makes the Alfabatik an unobtrusive day hike companion for the unexpected, especially if lined with a space blanket type product.

Disadvantages:

- Not as warm for the weight as Apex, when the Apex is new

- Expensive

Our sizing options can be configured to ensure an adequate fit with minimum down loft compression.