Sea to Summit Spark Ultralight Down Sleeping or Sea to Summit Ember Ultralight Down Backpacking? Which Sea to Summit Model to Buy

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You are comparing the sea to summit spark ultralight down sleeping vs ember ultralight down options. Both use 850 fill power down with Ultra-Dry treatment and 10D nylon shells for warmth and packability. They share an ultralight weight class and RDS certification. The main difference is design. The Spark is a contoured mummy bag. The Ember is an open quilt with attachment straps. This changes how you sleep and setup your gear.

Shape

Contoured mummy

Quilt

Temperature Rating

45°F

35°F

Weight

13.6 ounces

1.3 pounds

Lining Material

10D nylon

7D nylon

Setup Features

YKK zippers

Snap straps and drawcord

Choose the first if

• You prefer a traditional enclosed sleeping bag for cooler nights.
• You want a lighter pack weight under 14 ounces.
• You need a 45°F temperature rating for warm weather trips.

Choose the second if

• You want to use a quilt for better ventilation and movement.
• You need a lower 35°F rating for colder conditions.
• You plan to join two units together for a double bed.

Verdict

Choose the Spark if you want a lighter, enclosed bag for warmer weather. Pick the Ember if you need more warmth and the versatility of a quilt design. Both offer high-quality down insulation for ultralight backpacking.

Spark vs Ember Key Differences

Temperature Rating

Edge: Tie

The Sea to Summit Spark is rated for 45°F, making it suitable for warmer three-season conditions. The Sea to Summit Ember offers a lower 35°F rating, providing extra warmth for cooler nights. If you expect temperatures near freezing, the Ember’s lower limit gives you a safety margin. The Spark works best when nights stay mild. Choose the Spark for summer trips or high-elevation warmth. Pick the Ember when you need protection against colder air. Your local climate dictates which rating fits your needs.

Design and Shape

Edge: Tie

The Spark uses a contoured mummy shape with a hood and footbox. This design traps heat around your head and feet efficiently. The Ember is a quilt with snap-on attachment straps and a drawcord foot pocket. This open design reduces bulk and allows for easier movement. You can ventilate the quilt by opening the sides. The mummy bag seals you in for maximum warmth retention. Quilts offer versatility for varying sleep positions. Your preference for enclosed warmth versus open airflow determines the better shape for you.

Weight

Edge: Sea to Summit Spark 45°F Ultralight

The Spark weighs 13.6 ounces, which is extremely light for a sleeping bag. The Ember weighs 1.3 pounds, equaling 20.8 ounces. The Spark is significantly lighter by over seven ounces. This weight difference matters on long trails where every ounce counts. The Spark’s lighter profile helps reduce pack load. The Ember’s additional weight comes from its larger surface area and attachment hardware. If minimizing pack weight is your top priority, the Spark has a clear advantage. You save weight by choosing the bag over the quilt.

Setup and Compatibility

Edge: Sea to Summit Ember 35°F Quilt

The Spark is a self-contained unit that requires no extra gear to function. It keeps you warm immediately upon entering. The Ember relies on snap-on straps to secure it to your sleeping pad. This setup prevents the quilt from shifting during the night. You must ensure your pad is compatible with the strap system. The Ember also features press-studs to join two units together for couples. The Spark does not offer this linking capability. Your sleeping pad choice influences the Ember’s usability significantly.

Insulation and Materials

Edge: Tie

Both products use 850+ fill power down treated with Ultra-Dry technology for moisture resistance. The Spark features a 10D shell and 10D nylon liner. The Ember uses a 10D nylon shell with a lighter 7D nylon lining. The Ember’s lining is thinner, which may affect durability slightly but reduces weight. Both share RDS certification for ethical sourcing. The Spark’s liner is slightly heavier than the Ember’s. This difference is minor but contributes to the overall weight gap. Both materials provide excellent breathability and compression for backpacking.

Which Sea to Summit Bag Fits You

Warm-weather backpackers prioritizing minimal weight

Our pick: Sea to Summit Spark 45°F Ultralight

The Spark weighs 13.6 ounces and offers a 45°F rating. Its contoured mummy shape and 10D shell keep you warm without bulk. You get reliable YKK zippers and a lifetime guarantee. This model suits bike packing or summer trips where every ounce matters and temperatures stay mild.

Campers needing versatility and pad security

Our pick: Sea to Summit Ember 35°F Quilt

The Ember features a quilt design with snap-on attachment straps. These straps secure the gear to your sleeping pad, preventing shifts. You also get a drawcinch foot pocket and press-studs to join two quilts. This setup provides stability and flexibility for varied sleeping positions in cooler conditions.

Hikers facing cooler 35°F nights

Our pick: Sea to Summit Ember 35°F Quilt

With a 35°F temperature rating, the Ember handles cooler nights better than the Spark. It uses 850 fill power down in box baffles for consistent warmth. The 10D nylon shell and 7D lining balance weight and durability. You get extra insulation for two-season backpacking or higher elevation trips.

Specifications side by side

Spec	Sea to Summit Spark 45°F Ultralight	Sea to Summit Ember 35°F Quilt
Temperature Rating	45°F	35-degree Fahrenheit
Insulation Type	down	down
Shape	contoured mummy	quilt
Weight	13.6 ounces	1.3 pounds
Fill Power	850+ FP	850
Shell Material	10D	10D nylon
Lining Material	10D nylon	7D nylon
Intended Use	–	Backpacking
Color	Gray	Grau
Insulation Material	Down	Down
Weight Class	Ultralight	Ultralight
Dimensions	77.2 × 30.5 × 3 inches	15.4 × 9.06 × 6.3 inches
Size	Standard	Standard
Model	ASL041072-050101	S2221

Frequently asked questions

Which bag is lighter for ultralight trips?

The Sea to Summit Spark is lighter. It weighs 13.6 ounces. The Ember quilt weighs 1.3 pounds, which equals 20.8 ounces. You save 7.2 ounces by choosing the Spark. This weight difference matters for long-distance hikers. Every ounce counts when you carry gear all day. The Spark offers the lower weight for warm conditions.

Can the Spark keep me warm at night?

The Spark is rated for 45°F. It works well for warm-weather ultralight backpacking. It uses 850 fill power down for efficient warmth. The 10D nylon shell adds light protection. You should not use it in freezing temperatures. Choose this model only if you expect mild nights. It prioritizes low weight over extreme cold protection.

Is the Ember a full bag or a quilt?

The Ember is a quilt. It does not have a full envelope shape. You wrap it around yourself for warmth. This design saves weight compared to a mummy bag. The Spark is a standard sleeping bag. It encloses you fully. Pick the quilt if you prefer adaptable coverage. Pick the bag if you want a traditional sealed environment.

What is the packed size difference?

The Spark packs smaller than the Ember. The Spark dimensions are 30.5 by 3 by 77.2 inches when expanded. The Ember packs to 9.06 by 6.3 by 15.4 inches. The Spark is designed for minimal bulk. The Ember is also ultralight but slightly larger when compressed. You get the most compact option with the Spark for warm weather.

Who should buy the Ember instead?

Buy the Ember if you are under six feet tall. It is designed for ultralight backpackers under that height. It offers a 35°F rating for cooler nights. You get reliable down performance in mild conditions. The Spark fits a broader range of temperatures. The Ember targets specific hikers who need extra warmth without heavy gear.

Does the Spark use high-quality down?

Yes, the Spark uses 850 fill power down. This high loft provides excellent warmth for its weight. The down is treated with Ultra-Dry technology. This helps maintain insulation when damp. The 10D nylon shell keeps the bag light. You get premium insulation in a very light package. It is built for hikers who value efficiency.

Which model is better for summer camping?

The Spark is better for summer camping. It is rated for 45°F. This suits warm-weather ultralight backpacking. You will not overheat with this bag. The Ember is rated for 35°F. It may be too warm for hot nights. Choose the Spark for summer trips. It balances warmth and breathability for higher temperatures.

See also

• sea to summit vs featherstone sleeping bag
• best sea to summit 0f sleeping bags
• down vs feather comforter
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