Crash Lock Boxes: are they the Best for Ecommerce?
- , by Joe Wille
- 7 min reading time

First off, what are crash lock boxes? The word "crash" in "crash lock box" perfectly explains the action by which the box is assembled — you first expand the box, then you push your hand down into the base of the box, often slamming it onto the packing bench in a downwards crashing motion, which in turn locks the tabs into place leaving you with an assembled box.
Crash Lock Boxes, made for Ecommerce
Crash lock boxes are the go-to for ecommerce shipments, especially as they are among the fastest modes of packing boxed orders of goods for dispatch by hand. Crash locks are easy to assemble and do not require additional tape, unlike standard cardboard boxes.
Some crash lock boxes also feature a built-in peel and seal strip along the top of the lid, so you can save money and waste by negating the need for packing tape entirely.
This means business could save money both on time and labour costs, as well as reducing your need for packaging consumables such as tape.
What's more, some crash lock boxes also feature variable height creases along the walls of the box, so you can reduce the internal dimensions of the box and use less void fill material.
Bespoke Printing Crash Lock Boxes
Manufactured as they are from corrugated cardboard, crash lock boxes can be branded on the inside or the outside of the box. Typically, they are printed in two colours using flexographic printing and often, the clever use of a white or natural kraft cardboard can be incorporated into the design as a third colour.
However, if you're looking for high-end metallics, textured material "flock" finishes or special block foils, you can apply lithographically printed laminations.
Litho lamination is a process through which high-end Lithographic printers print your artwork directly onto a premium paper; that paper is then bonded to the corrugated cardboard before it goes through a die cutter to be cut out. Finally, it’s passed through the gluer machine for finishing.
Litho vs Flexo — there's only one choice for sustainability when printing on Corrugate
We often recommend that customers go for flexographic printing, simply because it's more cost effective, way more environmentally friendly (uses plant and water based inks) and consumes much less energy to manufacture when compared with Lithographic laminations; as you can often print and cut in a single pass.
Lithographic laminations, especially those with special colours, often contain a plastic element that can render the box almost impossible to recycle — a big no-no in terms of sustainability.
What are the limitations of Crash Lock Boxes?
Crash locks are great, and as shown above, they definitely serve a purpose, but they do come with some inherent flaws worth noting before deciding which box is best for your ecommerce business.
1. Security
It is possible to put your hand up through the base of a standard crash lock box and remove the product inside. Once the item has been removed from the box, it's relatively straightforward to reseal the base, so that externally it still looks like an intact box.
This could present an issue for those shipping small, high-value items, such as premium cosmetics. This is why, for some ecommerce packaging designs, being tamper evident is a major selling point.
Our crash lock boxes do not have this flaw as they feature a patented interlocking base. The crash lock base incorporates hooks that fold into one another making it virtually impossible to compromise the base without visibly tearing open the box.
2. Production costs and size
Crash lock boxes use a large amount of material in order to produce a relatively small box (referred to as having a "large blank size"). This can make them slightly more expensive to manufacture than say your standard 0201 corrugated cardboard boxes.
Due to this large blank size, some manufacturers have a size limitation when producing crash lock boxes; often, larger boxes are made in two parts and glued or stapled together at a later stage (sometimes by hand), further increasing per unit costs.
When weighing up the cost vs benefits of crash lock boxes against any other form of packaging, it is important to factor in labour savings, reduced tape consumption and consolidation of consumables when factoring in per unit price.
You might find that the unit cost, which could be over that of standard postal packaging, is often offset by the improvement in efficiency benefits to your ecommerce business.

3. Void fill
Crash lock cardboard boxes have no integrated retention feature, so you often have to invest in high speed paper void fill dispensers. These could also include packing peanuts and kraft paper rolls to help fill the air gap around your products.
Void fill can be expensive both in terms of time and storage, but it is also hard to manage as consumption varies considerably based on how many items there are per dispatch.
What's the best alternative to Crash Lock Boxes?
We've developed the FlyPak, a new type of ecommerce packaging, in order to specifically address the issue of increased void fill consumption inherent with crash lock boxes. Additionally, the FlyPak has none of the security flaws of a standard crash lock box.
Postal boxes with integrated retention
Featuring integrated "wings" that fold over retaining the product inside, this new type of postal packaging will significantly reduce or even remove the need for void fill. For additional security, it also features triple thick solid sidewalls and interlocking tamper-evident tabs.
Packaging that optimises warehouse storage
In its supplied form, the FlyPak is only 2 ply high and it stacks very well when palletised (much like a standard book wrap mailer). Efficient palletisation means storage space is reduced when compared to crash lock boxes.
Cheaper & more effective than a Crash Lock box
Despite having all of these additional benefits, FlyPak is actually easier to manufacture than a standard crash lock box. This results in a cost neutral or cheaper upgrade from crash lock boxes, as a similar amount of material is used.
You can also save money on tooling and print costs by printing FlyPak single sided yet still achieve a design on both the outside and the inside of the box. By printing marketing messages onto the integrated retention wings, you can ensure that all-important unboxing experience for considerably less cost than a double-sided printed crash lock box.
To learn more about our FlyPak alternative to crash lock boxes, click here.