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If your backpack doesn’t have convenience pockets for your camera and snacks, here is a good way to add them.


by Will Rietveld and Janet Reichl | 2006-09-11 03:00:00-06


The simBLISSity UnSlack Pack is an accessory pouch with two pockets that attaches to a backpack’s shoulder strap or hipbelt. It is intended for use with backpacks that do not have enough (or any) convenient storage pockets to hold a digital camera, map, snacks, and other frequently used smaller items. It’s also claimed to securely hold a water bottle up to about 24 ounces. Obviously, the challenge of designing an add-on accessory is making it fit most any backpack and making it fit securely so it doesn’t flop around.

simBLISSity UnSlack Pack SPOTLITE REVIEW - 1
The simBLISSity UnSlack Pack is an add-on pouch that attaches to a shoulder strap or hipbelt. Its main compartment is 70d silicone-coated ripstop nylon, and the front pocket is mesh. Both pockets have a hook and loop closure; the main one also has a snap.

Before I get into the utility and performance of the UnSlack Pack, let’s look at its design and features. It measures 5.5 inches wide x 6 inches high x about 2 inches thick. The main body (main pocket) is made of 70-denier silicone-coated ripstop nylon. A bellowed nylon mesh pocket is attached to the front. The closure on the main pocket is a “gentle touch” hook and loop strip, plus a snap; the closure on the front mesh pocket is a regular hook and loop strip. There are two webbing loops at the top for attaching a mounting strap, plus an elastic cord tightening system wrapped around the outside.

An optional Hipbelt Kit ($2.55 / 0.5 ounce) is available to attach and secure the UnSlack Pack to a wider hipbelt (8-inch + circumference). It contains a longer webbing strap and elastic cord.

Attaching the UnSlack Pack was the first obstacle we encountered. It comes with three pages of description and instructions (in fine print) explaining lots of options, so the process seemed daunting at first. However, once we mastered the instructions, we were able to fit the UnSlack Pack to every pack we tried it on. Shoulder strap attachment was easy on packs that have a webbing daisy chain on the front of the strap. On packs without that feature, we found that the sternum strap provided a good anchoring point.

simBLISSity UnSlack Pack SPOTLITE REVIEW - 2
Underside of a shoulder strap showing how the UnSlack Pack is attached. An included short webbing strap is used at the top and an elastic cord is wrapped around the shoulder strap and body of the pack to secure it. On the Gossamer Gear G5 pack shown, the sternum strap is used as an anchor to keep the pocket from sliding down.

On the trail, both of us found the UnSlack Pack very useful:

(Will’s Comments) “I preferred to use it on my left shoulder strap at sternum strap height to hold a 20-ounce water bottle - the type that bottled water comes in. The elastic cord on the outside of the pack stabilizes it very well, and prevents it from falling out when I lean over. Alternatively, I carried a Platypus hydration system in a side pocket, and used the UnSlack Pack on a shoulder strap for my digital camera, topo map, snacks, and my notebook for recording gear notes. I didn’t like it as well mounted horizontally on a hipbelt because it was a little harder to access and my arm bumped against it.”

(Janet’s Comments) “None of my frameless packs have any convenience pockets, so I found the UnSlack Pack very handy to carry a digital camera, sunscreen, lip balm, thin gloves, snacks, etc. I prefer to carry my water bottle in a nylon pouch on my hipbelt, so the UnSlack Pack worked best for me mounted on a shoulder strap. The ‘gentle touch’ Velcro on the main compartment is easy to open, but it’s important to close the snap so things don’t fall out. The regular Velcro closure on the mesh pocket is hard to pull apart, and catches on clothing.”

simBLISSity UnSlack Pack SPOTLITE REVIEW - 3
The UnSlack Pack attached to a shoulder strap carried a 20-ounce water bottle (left) or a digital camera and other essentials (right) equally well. The elastic cord on the outside held it securely in place so it didn’t flop.

As designed, the UnSlack Pack mounts horizontally on a hipbelt. Since most packs have padding over the hips and a webbing belt in front, it means that the UnSlack Pack locates at your side where it interferes with arm movement. We found that we could adjust our arm movements to accommodate the pack. A water bottle in that position got in the way more and had a tendency to fall out, unless the elastic cord was really tight. It worked well loaded with a digital camera and an assortment of small items - to access the pack simply loosen the elastic cord and the pack tilts up for easier entry. We tried mounting the pack vertically on the hipbelt, but found that it does not stay in place very well. For hipbelt mounting, simBLISSity might consider designing another version of the UnSlack Pack with top access instead of side access.

simBLISSity UnSlack Pack SPOTLITE REVIEW - 4
The UnSlack Pack is designed to mount horizontally on a hipbelt. The photos show it mounted on a Gossamer Gear G5 pack (left), and a 2006 Osprey Aether 60 pack (right). In both cases the accessory pack locates more to the side where it interferes with arm movements.

Although the pack’s main compartment is waterproof silicone-coated nylon, the closure is not waterproof, especially when mounted vertically on a shoulder strap. The front mesh pocket is not waterproof at all. Thus it is necessary to carry a zip-lock plastic bag or two to put things into when it rains. The main pocket also does not have any water drainage, so it can accumulate water.

Overall, we found the UnSlack Pack very useful on backpacks that do not have any convenience pockets. As designed, we found that it works best when mounted on a shoulder strap.

Specifications and Features

  • Manufacturer: simBLISSity Ultralight (
  • Year/Model: 2006 UnSlack Pack
  • Style: accessory pocket that attaches to a shoulder strap or hipbelt
  • Size: 5.5 inches wide x 6 inches high x approx. 2 inches thick
  • Materials: 70d silicone-coated ripstop nylon, nylon mesh, nylon webbing, one snap, elastic cord, hook and loop closures
  • Included: pack, short attachment strap, elastic cord with micro-cordlock
  • Volume: 35 cubic inch main compartment + 15 cubic inch mesh pocket
  • Weight: measured weight is 0.85 oz, manufacturer claimed weight is 0.8 ounce
  • MSRP: $21.95, hipbelt mounting kit $2.55


"simBLISSity UnSlack Pack SPOTLITE REVIEW," by Will Rietveld and Janet Reichl. (ISSN 1537-0364)., 2006-09-11 03:00:00-06.