Brands that manufacture military tactical backpacks use different fabric and material, so some are more waterproof whereas some are less waterproof. You will have to research about the fabric and material before buying one.

Most tactical backpacks are made from 600D – 1000D polyester or nylon, so generally they are water-resistant, but not completely waterproof. If any type of brand advertises its backpacks as 100% waterproof, it’s better to be skeptical and look into the finer details because it is not necessarily the whole truth.

Article of interest: Best water-proof tactical backpacks

Most commonly fabric used for tactical backpacks

Polyester

600D thread count polyester is very common in budget tactical backpacks. Polyester backpacks have a rough and rugged look about them which is perfect for military style, but it’s a little heavier than other fabrics and not 100% waterproof.

Advantages:

  • Cheap and affordable
  • Hydrophobic and water repelling
  • Wrinkle & tear resistant

Disadvantages

  • Heavier fabric
  • Rigid and less flexible
  • Less elegant

You can’t go too wrong with Polyester 600D military backpacks if you are looking for an affordable and budget friendly backpack that is “water-proof”. It is water-resistant and repels water when caught in the rain or if you happen to splash water on it.

However, if you fall into a pool of water or happen to be out in the rain for a longer period of time, eventually a polyester backpack will get wet and anything inside the backpack will most certainly get wet.

Nylon

Nylon has a glossier look and usually has less thread count than polyester, but it’s also a common fabric used for backpacks.

Advantages:

  • Light weight fabric
  • Stretchy and flexible
  • Tear and wrinkle resistant

Disadvantages

  • Absorbs water and can get heavier
  • Glossy, shiny appearance (can be a disadvantage or an advantage depending on your preference)
  • Not as environmentally friendly

Nylon tactical backpacks in my opinion look a little better design wise and the fabric is more breathable meaning it’s less likely to smell, but from a water-proof stand point, polyester is the better choice if you are going for practicality.

However, some nylon backpacks are coated with DWR which does make it more water-proof.

Read: Nylon vs Polyester

Canvas

Another common fabric for military tactical backpacks is canvas. Compared to the other fabrics, canvas looks the most vintage, rugged, and tough looking.

Canvas can also be a good water-resistant backpack choice, but it’s still not 100% waterproof.

Advantages:

  • Heavy duty fabric
  • Tear and wrinkle resistant
  • Water-resistant and ab

Disadvantages

  • Heavier and thicker fabric
  • Rigid and flexible

When buying a canvas tactical backpack, make sure to check whether it was treated with water-proof coating. Canvas can be chemically treated and is quite a durable material.

Read: What is canvas

Other things to consider for “water-proofness”

Zippers: Zippers that have a layer over it is more water-resistant

Pockets: Look for pockets that might catch water and leak into the main backpack compartment

Backside: The mesh and the cushion of the backside of the backpack may not be as water-proof depending on the make.