Arc UL 20°F - 15°F Custom Page

New product


The Arc UL quilts are designed for optimal efficiency in the environments met by long distance hikers.Custom features including sizing and weight saving options. 

More details


Add to wishlist

Pay via Credit Card or Paypal Account
Pay via Credit Card or Paypal Account


A few things to keep in mind:

  1. We measure the actual width from the finished quilt's inside, without stretching. 
  2. The differential cut makes the inside narrower/shorter than the outside.
  3. Our sizes are real life, so will get you a quilt generally wider/longer than other brands with similar specs.
  4. The measured length does not include the draft collar.

Appropriate use

These quilts are designed to provide sleeping comfort in the western US mountains from April to October. 

The 20° rated Arc UL is the standard go-to, do anything quilt. Our most popular choice for long-distance hikers ready to keep going into fall.

With the 15°F quilt cold sleepers get a boost in loft.

30°F and 25°F quilts are available here

Fill and Loft

The 900 fp down loft is a between 2.60” and 2.95”.  Fill volumes for either level are detailed in the charts.


The length is in 4" increments. The chart numbers interprets where the quilt top is when on your back. In open mode reaching just the chin level is the absolute shortest anyone should go, and then only on quilts for the warmer seasons. Reaching the user's forehead is the best compromise of low weight - efficient coverage. As always size up if in doubt. Bags and quilts cut too short tends to compress the foot area insulation to the detriment of cold toes.

Adequate width in the shoulder to hip region is crucial for sleep comfort and draft control. A ball park figure to achieve optimal performance is your shoulder circumference plus 6"-10". The Arc UL does not taper inwards until below hip level.

Newcomers to backcountry quilts can also experiment with a blanket before committing to a width. 

Foot End Design

The traditional Arc design is a permanently closed section finished with a round bottom piece sewn in place. A design common with high-end mummy bags.

Shell Material Choices

More details on the Fabric Page, found in the top menu under Materials.

Ultralight: 10d ultralight breathable shell. 

This ultralight fabric creates a comfortable sleep environment at the lowest weight. While providing very little protection from moisture, the superior breathability allows it to dry quickly in the sun. Ideal for users seeking the lowest weight.

Classic: 15d lightweight breathable shell.

Same non-existent moisture protection as the 10d above, but a significant increase in durability and tear strength. Expect a weight gain up to one ounce, depending on size.

Moisture protection for select areas: 7d ultralight waterproof/breathable shell.  

With 7d wp/b covering the outer foot section and top draft collar you can protect the down where it typically wets out the most, while leaving the large mid section fully breathable. For use in the modern single wall tent where rampant condensation often collides with the lower end of sleeping bags. Also, the draft collar is protected from moist exhalations. A very versatile setup.

The 7d wp/b is coated fabric, yet has a very light denier count, and as such adds under 5% to the total weight over the 10d option.

Liner Material Choices

Long term wear on quilt fabrics is most pronounced on the inside liner material. To anticipate this the Arc UL can be upgraded to our soft, durable 20d Taffeta black liner, specifically developed for sleeping bags. Expect one ounce of weight gain.


This optional synthetic Apex insulated bag is a booster option for extending the use of your quilt well into the colder season, while providing superior moisture management. 

Depending on the user the overbag can add 15°F or more to the rating of your base quilt, while completely eliminating drafts. The latter is probably the most crucial element for a winter specific quilt based sleep system; and very hard to maintain with a quilt/quilt setup.

The dampness inevitably forming on the outer surface will mostly affect the quick drying synthetic while the down mass stays drier. This applies to body moisture pushed outward; and dew, frost and shelter induced condensation from the environment. For longer trips in inclement conditions this becomes a crucial aspect of staying warm. 

This overbag is zipper-less with a closed mummy style foot box, and features a custom cut to match your quilt sizing specs and curvature thus avoiding excessive compression of the lofted down. A draw cord at the top seals in the warmth. It uses 2.5 oz weight Apex. 

The fabric used is a highly breathable 10d nylon, with smooth taffeta inside and ripstop out. All black. Average weight is 15oz, with small variances depending on the base quilt.

Additional applications includes emergency and summer stand alone use.

The overbag is also available for purchase at a later day here

What's in the box?

The quilt, a set of quilt straps, a silnylon stuffsack and a large breathable storage sack.

We also have additional articles with helpful pointers on selection and design:

Choosing the right Quilt

Designing with Down

Why Overfill?

Go to the bottom of this page for the full Arc UL Configuration Menu.

Write a review

Arc UL 20°F - 15°F Custom Page

Arc UL 20°F - 15°F Custom Page


The Arc UL quilts are designed for optimal efficiency in the environments met by long distance hikers.Custom features including sizing and weight saving options. 

Product Options
Temperature Rating

The rating reflects the lowest temperature during which a well conditioned hiker can expect to remain comfortable throughout a full night. Adequate shelter and ground pad must be used.

20°F / -7°C. Includes differential cut
15°F / -10°C. Includes differential cut
Inside Length
62" - Extra Small
66" - Small
70" - Medium
74" - Long
78" - Extra Long
Shoulder Width
50" Our narrowest size for slim folks who doesn’t toss and turn much; and experienced quilt users wishing to save weight.
56" The most popular size that fits most frames.
62" For bigger people and/or those who toss and turn.
68" Very wide quilt - sprawling coverage!
Footbox Size Circumference
Shell Material

Moroccan Blue Ripstop 10d - Lightest, most breathable
Grey Ripstop 10d - Lightest, most breathable
Purple Ripstop 10d - Lightest, most breathable
Forest Green Ripstop 10d - Lightest, most breathable
Dark Olive Ripstop 10d - Lightest, most breathable
Brilliant Blue Ripstop 15d - More durable, breathable
Black Ripstop 15d - More durable, breathable
Purple Ripstop 15d - More durable, breathable
Dark Olive 15d - More durable, breathable
Liner Material Options
Black 10d taffeta - Lightest, most breathable
Black 20d taffeta - Durable, soft and comfortable but about an ounce heavier!
10d black taffeta in torso section, more durable 20d taffeta in foot section
Down Type

Allied Expedry is a moisture resistant goose down treated with a chemical free, safe compound. Expedry helps reduce drying times while minimizing performance issues in wet weather. The treatment is long lasting and effective.

Untreated 900fp goose down only available on request.

900 Fill Power Goose Down, Expedry, RDS Certified
Down Overfill

Adding overfill can prolong the life of the down, help maintain loft during moist conditions, boost the temperature rating by a small amount and keep the down volume from shifting. For most quilts/bags the overfill amount ranges from 45-65 grams of extra down

No Thanks
Overfill in foot section
Overfill in torso section
Overfill evenly throughout
Edge Tension Control

This design involves two user adjustable shock cords running lengthwise along the left and right quilt edges. On cold nights tension the cords to shorten the edges and draw them under you; during milder conditions completely slacken the cords to have the blanket throw feel. 

Strap package
Yes, include pad attach and under-body straps
Stuff Sack
Yes, please include a stuff sack
No stuff sack