Introduction: Cow Boxes - Recycle the Milk- Cartonway


I'd like to introduce with this project another way to combine 3D print with the use of material that commonly gets thrown into trash or recycle bin. As the result we will save printing material and reuse precious material that was supposed to get used only one time.

Here i want to show you how to make little boxes with 4 easy to print parts and a empty milk carton. I think every household and workshop can't have enough boxes to store little stuff laying around. Why buying new ones when we can made them with less new material and low cost?

A clever material:
Milk and beverage cartons usually are a laminated combination of aluminum, cardboard and plastic foils.

This "raw material" is stable enough for tiny boxes and easy to cut with scissors. Also the surface is smooth, easy to clean, water resistant and insensible.

Introducing: The common 1 liter milk carton

The cartons i use are sold in every supermarket in Germany and sure in other countries too. Those have a square size bottoms with 70x70 mm or 72x72 mm. The usable height is ~ 190 mm. With this height we can make one lager or two small boxes.

Thoughts out of the box:

The height of the box is determined by the printed parts to 50mm which in my opinion is a useful height. Don't hesitate to create other versions with different height or other milk carton shapes.

The length can vary depending on your decision.

The open long side is folded to have a clean and not sharp surface. Also a open cut of the carton will soak water or dirt and blows out then.

Nevertheless, the box is not 100% waterproof to keep water inside. If you plan to plant some kitchen herbs inside, you have to fill the gaps with silicone before assembling.

Step 1: Print or Let It Print..

Sizes and shapes:

The print parts come in two sizes depending to your milk package. I figured out that there are mainly

two sizes of square-bottom packages sold in the supermarkets. 72 mm and 70 mm edge length. Mostly 70mm for fresh milk and 72 mm for long-term storage milk.

Don't forget the caliper on your next food shopping Saturday ;)

Print instructions:

Print the frames and inlets with min 2 perimeters and min 0.3 mm layer height. After printing keep an eye on the parts if there are some blobs to cut away.

The introduced boxes where printed with HD Glass from formfutra. Beside it's transparent look the material is strong, ductile and ideal for clamping fixation.

The code:

the freeCad files can get used to make other shapes or improvements. Please respect the license terms of CC.

Step 2: Cut and Go

Tools we need:

  • Tailor scissors - for even long cuts.
  • Steel ruler

  • Cutter

  • A waterproof fine liner
  • 4 x Paper clips


After cleaning the carton inside with water and dish-liquid, dismantle it carefully like shown on the photo. Dry it with a cloth or towel.

In most cases the tip of the carton can ripped off by hand. The bottom maybe has to be cut with the sharp cutter, close to the edge.

If there is a welding crease, make the bottom-to-top cut on a place that the crease points finally to one outlaying edge.

Not like on my photo :(

Step 3: Little Geometry Lesson

At the drawing table:

Draw with the ruler and the pen the lines like shown on the photo. Pay a little attention to the notes if you like.

Imagine that the surface in the middle will be the floor. Draw now horizontally one line downwards on 5cm and one on 6 cm. Do the same upwards. You can use the given creases as reference.

Now draw 3 lines vertically. Two to limit the left and right edge on a clean point. One in the middle to set the future length of the box. At least you decide if yo will have two boxes with the same size, two different or one large.

Cut now along the lines (with the exception of the 5cm lines) the carton into two pieces. Don't throw away the left-over piece. With this part we will fill the front and rear walls.

Finlay take care for a perfect geometry and avoid sloping lines. Use an plane-angle too keep it all parallel. Sloping lines and cuts will result in warped boxes.

Little hint:

If you think it looks cooler, you can build it inside-out that the aluminum surface shows outside (if the carton has one).

In this case you have to draw all on the printed side.

Also the lines can wiped away with alcohol after cutting.

Side note:

some clever brains sure will ask why i don't draw the back and front latches too, to have one piece per box.

First it will need more material per cut out and there could be made only one box per milk carton. The fourth surface also is left in every case.

Second you will have the free choice which interesting looking part will appear on the front or back side.

Anyway, feel free to create your own cutting pattern ;)

Step 4: Fold and Clip

Final assembling:

Push the both 1 cm lines downwards by clamping it between the ruler and the tables edge. Fold them now 180° back. These foldings will appear later as a stable and smooth edge on the top of the box.

Clamp the both folded edges now with the paper clips to keep them in place while assembling. If you like you can add some glue in between before clamping.

Cut from the left-over material two pieces that fit into the two frames. Maybe you'll find an interesting pattern for it.

Insert the folded main part into the frame and fiddle in the inlet first on the bottom of the box.

The inlet has two tiny gaps. These have to point to the top of the box to keep the folded edges.

Keep it with one finger on place, flip the inlet down and press it firmly into the frame. Maybe you will need a screwdriver to push it down. Take care that you don't get hurt by a slipped screwdriver.

Replay the same on the other side of the box. If everything has gone right, the box will stay stable without get glued together.

Congratulations, your first box has finished!