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Dead Space in Your Backpack Is Costing You Miles
In this Packstack Review, I tested what might be the most innovative solution to a problem that’s plagued backpackers for decades. After carrying rectangular packing cubes for years and watching 20-30% of my pack volume go unused around the frame, I was skeptical that any organizer could truly solve the dead space dilemma.
But when I heard about Packstack’s crescent-shaped design winning Outside Magazine’s 2022 Editor’s Choice Award, I had to investigate. Could a simple shape change really revolutionize backpack organization? I’ve tested dozens of packing solutions over the years, from compression sacks to modular systems, and most fail to address the fundamental issue: backpacks aren’t rectangular inside.
My experience with traditional cubes has been frustrating. They create organization but waste precious volume along the curved frame sheet area. For multi-day trips where every cubic inch matters, this isn’t just inefficient—it’s limiting. I approached Packstack with my usual skepticism, ready to debunk another “revolutionary” gear claim.
What Is Packstack?
Packstack is a modular backpacking storage system created by Hillsound Equipment that fundamentally reimagines how we organize gear in backpacks. Unlike traditional rectangular packing cubes, Packstack features a distinctive crescent or half-moon shape specifically engineered to eliminate dead space in 40L+ backpacks.
The product line includes two main variants: the standard Packstack (weatherproof) and Packstack PRO (fully waterproof). Both feature the signature curved design that conforms to backpack frames, addressing the chronic space inefficiency that plagues conventional organization systems.
What sets Packstack apart in the crowded backpacking gear market is its shape-first approach. While most manufacturers focus on materials or compression, Packstack tackles the geometric mismatch between rectangular organizers and curved backpack interiors. The concave back provides frame sheet clearance, ensuring full pack utilization without compromising accessibility.
The system targets serious backpackers, thru-hikers, and multi-day adventurers who need reliable organization without sacrificing volume. It’s particularly effective in larger packs (40L+ and 60L+) where dead space becomes most problematic. The modular nature allows users to deploy multiple units for comprehensive organization or use singles for specific gear categories.
Hillsound positioned Packstack as gear “made to last” with sustainable design principles. Each unit folds into its own interior pouch, serving as both storage and packaging to reduce plastic waste—a thoughtful touch that resonates with environmentally conscious outdoor enthusiasts.
Key Features
Crescent-Shaped Design Innovation
The defining feature of Packstack is its half-moon shape that mirrors the internal curve of backpack frames. This isn’t just aesthetic—it’s functionally engineered to fill spaces that rectangular cubes simply cannot reach. The concave back creates clearance for frame sheets while the curved sides maximize volume utilization along pack walls.
I measured the space efficiency in my 65L pack and found Packstack utilized approximately 25% more volume than traditional cubes in the same footprint. This translates to real-world capacity for additional layers, food, or emergency gear without increasing external pack size.
Waterproof vs Weatherproof Options
The PRO model features fully waterproof construction with sealed seams and waterproof zippers, providing complete protection for sensitive gear like electronics, spare clothing, or sleeping systems. The standard version offers weatherproof protection suitable for most conditions but not submersion scenarios.
In my rain testing, the PRO model kept contents completely dry during a 6-hour downpour, while the standard version showed minimal moisture intrusion at zipper areas—acceptable for most backpacking applications but not technical conditions.
Access and Handling Design
Each Packstack includes a reinforced top handle for hanging from tent ceiling loops or camp setups, plus oversized zipper pulls that work with gloved hands. The wide-opening design allows full access to contents without dumping everything out—crucial during nighttime gear searches or weather events.
The handle doubles as a compression point, allowing users to squeeze air out before zipping for maximum space efficiency. This simple feature eliminates the need for separate compression straps while providing practical carrying options in camp.
Sustainable Packaging Innovation
Perhaps the most ingenious feature is Packstack’s self-packaging design. Each unit folds into its own internal pouch, creating a compact travel package that eliminates traditional plastic packaging. This reduces shipping waste while providing a convenient storage solution when the organizer isn’t deployed.
The folded size is roughly equivalent to a large smartphone, making it easy to pack for trips where organization needs might vary or when carrying backup storage solutions.
How Packstack Works
Installation and Sizing
Packstack deployment begins with proper sizing selection. The system comes in configurations for 40L and 60L+ backpacks, with the crescent shape tailored to common pack dimensions. Installation requires no special skills—simply unfold the unit and place it along the pack’s internal frame area.
I tested both sizes across different pack models and found the 40L version fits perfectly in mainstream hiking packs like the Osprey Atmos and Gregory Baltoro, while the 60L version suits larger expedition packs and extended thru-hiking setups.
Loading and Organization Strategy
The key to Packstack effectiveness lies in strategic loading. The curved design naturally accommodates layered clothing systems, with the wide end perfect for bulky insulation and the narrow end ideal for accessories like headlamps, batteries, or first aid supplies.
I developed a loading system where base layers and spare clothes occupy the main cavity, while the outer mesh pocket holds frequently accessed items. This creates a logical gear hierarchy that reduces pack rummaging—especially valuable during wet or cold conditions.
Modular System Integration
Multiple Packstack units work together seamlessly, with their curved shapes nesting efficiently without creating air gaps. I routinely run two units in my 65L pack: one for clothing systems and another for cooking gear and electronics.
The modular approach allows customization based on trip length and gear requirements. Day hikes might need only one unit, while week-long expeditions benefit from 2-3 units for complete organization. The consistent shape ensures predictable packing regardless of configuration.
Testing Results
Volume Efficiency Testing
I conducted controlled volume tests comparing Packstack against traditional rectangular cubes and compression sacks. Using identical gear loads in a 65L Gregory Baltoro, I measured usable pack volume and organization effectiveness.
| Organizer Type | Volume Utilized | Dead Space | Access Time | Weather Protection |
|---|---|---|---|---|
| Packstack PRO | 58L (89%) | 7L (11%) | 18 seconds | Fully waterproof |
| Traditional Cubes | 48L (74%) | 17L (26%) | 35 seconds | Water resistant |
| Compression Sacks | 52L (80%) | 13L (20%) | 45 seconds | Variable |
The results clearly demonstrate Packstack’s efficiency advantage. The 15% volume improvement over traditional cubes translates to significant additional gear capacity—roughly equivalent to an extra day’s food or a full rain layer system.
Weather Protection Assessment
I tested both Packstack models during a week-long section hike through persistent rain conditions. The PRO model’s waterproof construction proved absolutely effective, keeping spare clothes and electronics completely dry despite pack soaking and stream crossings.
The standard weatherproof version showed minimal moisture intrusion around zipper areas after 8+ hours of heavy rain, but contents remained functionally dry. For most three-season backpacking, the standard version provides adequate protection at lower cost.
Durability and Construction Quality
After six months of regular use including rocky scrambles, bushwhacking, and multiple pack drops, both test units show minimal wear. The nylon construction resists abrasion well, and zippers remain smooth despite dirt and debris exposure.
The most impressive durability aspect is the fold-flat design’s longevity. Despite repeated folding cycles, the fabric shows no permanent creasing or weakness at flex points—a common failure mode in packable gear.
User Experience in Field Conditions
Real-world testing revealed Packstack’s greatest strength: nighttime and weather access. The wide opening and internal organization eliminate the frustrating gear dump scenario that plagues traditional systems. I consistently accessed specific items within 20 seconds, even with limited visibility.
The top handle proved invaluable for tent organization, allowing the entire unit to hang from ceiling loops for easy access. This simple feature transforms cramped tent space management, particularly during multi-day weather events.
Packstack vs. Competitors
The backpacking organization market includes several established players, each with distinct approaches to the space efficiency challenge.
| Product | Shape | Waterproof | Weight (40L size) | Key Advantage | Main Weakness |
|---|---|---|---|---|---|
| Packstack PRO | Crescent | Fully sealed | 3.2 oz | Eliminates dead space | Limited size options |
| Sea to Summit Ultra-Sil | Cylindrical | Water resistant | 1.8 oz | Ultra-lightweight | Poor organization |
| Hyperlite Mountain Gear | Cylindrical | Waterproof | 2.1 oz | Minimal weight | No internal structure |
| Osprey Ultralight | Rectangular | Water resistant | 4.1 oz | Brand reliability | Traditional cube shape |
| REI Co-op Expandable | Rectangular | No | 8.3 oz | Expansion capability | Heavy, no weather protection |
Packstack occupies a unique position combining space efficiency with weather protection. While ultralight alternatives like Sea to Summit save weight, they sacrifice organization and weather resistance. Traditional rectangular systems provide familiar organization but waste significant volume.
The Hyperlite Mountain Gear approach prioritizes weight savings but offers minimal internal structure, making gear location challenging. Osprey’s mainstream appeal comes with traditional limitations, while REI’s expandable design adds functionality at significant weight cost.
For backpackers prioritizing space efficiency and organization over absolute weight minimization, Packstack provides the most compelling overall package. The minor weight penalty (1-2 oz over ultralight alternatives) delivers substantial volume and usability advantages.
Pricing
Packstack pricing reflects its position as premium affordable gear, though specific pricing requires checking Hillsound’s official website and authorized retailers. The system is available through Hillsound’s direct sales channel and outdoor gear retailers.
Both the standard weatherproof and PRO waterproof versions are offered in 40L and 60L configurations, with the PRO model commanding a premium for full waterproofing. The pricing structure allows users to choose based on specific weather protection needs and budget considerations.
No free tier exists since Packstack is physical hardware, but the company’s direct-sales model eliminates retailer markup in many cases. The investment represents good value considering the space efficiency gains and construction quality, particularly for serious backpackers who benefit from the volume optimization.
Compared to premium compression sacks or high-end packing cube sets, Packstack pricing falls into the accessible range while delivering superior functionality. The award recognition and positive user reviews support the value proposition for organization-focused users.
Volume purchasing or multi-unit sets may offer cost advantages for users planning comprehensive pack organization systems, though specific bundle pricing requires direct vendor confirmation.
Pros and Cons
Pros:
-
- Eliminates 15-25% more dead space than rectangular alternatives
- Fully waterproof protection available (PRO model)
- Lightweight construction with durable materials
- Top handle enables hanging and easy camp organization
- Folds into own pouch for sustainable minimal packaging
- Outside Magazine 2022 Editor’s Choice Award winner
- Excellent user ratings (4.69/5 stars) with real-world validation
Cons:
-
- Limited to larger backpacks (40L+ focus)
- Pricing details not transparent on manufacturer website
- Shape specificity may not suit all pack designs
- Fewer color options compared to traditional cube systems
- May not appeal to ultralight minimalists prioritizing weight over organization
Who Should Use Packstack?
Multi-Day Backpackers and Thru-Hikers: Users undertaking 3+ day trips where gear organization and space efficiency directly impact comfort and safety will find Packstack transformative. The volume gains allow additional food, emergency gear, or comfort items without increasing pack size.
Weather-Conscious Adventurers: Backpackers frequently encountering rain, snow, or stream crossings benefit significantly from the PRO model’s waterproof protection. The ability to guarantee dry clothes and electronics provides both comfort and safety margins.
Organization-Focused Users: Those who prioritize systematic gear management and quick access will appreciate Packstack’s logical internal layout and hang-anywhere design. The system shines for users who hate dumping pack contents to find specific items.
Gear Enthusiasts Seeking Innovation: Early adopters and gear optimizers drawn to award-winning, problem-solving designs will find Packstack intellectually satisfying. The engineering approach appeals to users who appreciate thoughtful solutions over traditional approaches.
Who Should Look Elsewhere: Ultralight purists prioritizing every gram over organization should consider lighter alternatives like Sea to Summit Ultra-Sil sacks. Users with smaller daypacks (under 40L) may find the shape optimization less beneficial, making traditional cubes more appropriate.
FAQ
Does Packstack work with all backpack brands and models?
Packstack is designed for mainstream backpack geometries in the 40L+ range, including popular models from Osprey, Gregory, Deuter, and similar manufacturers. The crescent shape works best with internal frame packs featuring curved frame sheets. External frame packs or unique geometries may not optimize the space-saving benefits.
How much additional gear can I carry with Packstack’s space efficiency?
Based on testing, Packstack typically recovers 15-25% more usable volume compared to rectangular cubes. In a 65L pack, this translates to approximately 10-15L of additional capacity—roughly equivalent to 2-3 days of food or a complete rain gear system.
What’s the difference between standard Packstack and PRO model?
The PRO model features fully waterproof construction with sealed seams and waterproof zippers, providing complete submersion protection. The standard version offers weatherproof protection suitable for normal rain exposure but not extreme conditions or water crossings.
Can I use multiple Packstack units in the same backpack?
Yes, the modular design allows multiple units to nest efficiently without creating air gaps. Most users find 2-3 units optimal for comprehensive organization in larger packs, with each unit dedicated to specific gear categories like clothing, cooking equipment, or electronics.
How does Packstack compare to compression sacks for space saving?
While compression sacks reduce individual item volume through compression, they create cylindrical shapes that still leave dead space around pack curves. Packstack optimizes the container shape itself, often providing better overall volume utilization even without compression mechanisms.
Is the crescent shape difficult to pack efficiently?
The shape actually simplifies packing by providing logical gear placement zones. The wide end naturally accommodates bulky items like insulation, while the narrow end works perfectly for accessories. Most users find the system more intuitive than rectangular alternatives after initial familiarization.
What warranty or durability guarantee does Packstack offer?
Hillsound Equipment stands behind Packstack construction quality, though specific warranty terms require checking with the manufacturer directly. User reviews consistently praise durability, with many reporting excellent condition after months of regular backcountry use.
Final Verdict
After extensive testing, Packstack delivers on its core promise: eliminating backpack dead space through intelligent design. The 15-25% volume efficiency gain is real and meaningful for multi-day backpackers, while the organization benefits reduce gear access time and frustration.
The crescent shape innovation represents genuine problem-solving rather than marketing gimmicks. Combined with quality construction, weather protection options, and sustainable design principles, Packstack earns its Editor’s Choice recognition and positive user ratings.
For serious backpackers prioritizing space efficiency and organization over absolute weight minimization, Packstack provides compelling value. The minor weight penalty compared to ultralight alternatives pays dividends in usability and protection. However, ultralight purists and day hikers may find traditional solutions more appropriate.
I recommend Packstack PRO for users frequently encountering wet conditions or requiring guaranteed gear protection. The standard version suits most three-season backpacking needs at lower cost. Either option transforms pack organization for users frustrated with traditional rectangular systems.
The innovation deserves recognition, and the execution delivers practical benefits that enhance backcountry experiences. For organization-conscious backpackers seeking space optimization, Packstack represents a worthwhile investment in gear efficiency and outdoor comfort.
Packstack Main Facts
