How to Fold a Plastic Bag

Making a Triangle

Flatten the bag. Make sure to line up the sides of the bag so that the handles are parallel to each other. Pay attention to the way you orient the handles, as they play an important role in the folded triangle's structure. This is easiest to do on a hard, flat surface like your kitchen counter. If you're especially dexterous, you can try folding a triangle in the air without a flat surface. Just keep in mind this will be fairly difficult and you may just end up frustrating yourself. If you can't do it now, you may want to try again after you've had some practice folding. Do your best to get all of the air out of the bag. Run your hands across the bag to smooth it out.

Fold the bag lengthwise. Start by folding the bag in half so that the two handles perfectly overlap. Fold it again in the same direction, this time lining the edge opposite the handles on top of the other. Repeat this process until the entire bag has been folded into a roughly even rectangle the same width as the base of its handles. It should look like a narrow strip. Be sure to flatten the bag and squeeze the air out of it after each fold. The flatter the bag is, the easier it will be to fold into a triangle. The number of times you'll need to fold the bag lengthwise will depend on its size and the shape of its handles. This step typically takes a total of two or three folds.

Fold a bottom corner of the rectangle. Choose a corner of the bag at the edge opposite the handles. Fold the corner over to meet the other side to form a triangle. Flatten and smooth out the triangle you've just formed. At this point, the overall shape of your folded bag should look like a rectangle that shares one shorter edge with a much smaller isosceles right triangle.

Fold the triangle inward to make a new triangle. Take the free corner of the triangle and fold it inwards, turning its base into a new crease. The overall shape of the bag should once again be a narrow strip or rectangle. This method is similar to the technique used to fold a flag.

Keep folding the bottom edge inward over itself. Repeat the last two steps, rolling the triangle along the length of the bag. Keep going until you reach the near end of the handles. Make sure to leave enough of the bag unfolded for one last triangle fold. You should be making a new isosceles right triangle to add to your "stack" of triangles with each fold. Don't forget to smooth and flatten every time you fold. If your triangle is too puffy, it will not hold together.

Tuck the handles into the triangle. Make one last triangle fold, wrapping the tail of the bag around. Carefully stick the loose end into the pocket formed by the "roll" of triangles. As always, smooth out your triangle for the neatest, most stable shape possible.

Repeat with your other bags and store. Turn the rest of your bag collection into triangles. Now that your bags take up much less room, they should be a lot easier to store. You can keep them anywhere you'd like. You can neatly arrange your triangles in a basket on your kitchen counter or simply toss them into a bin under your sink. The choice is up to you.

Unfold each bag for use. As pretty as your triangle bags are, you can't use them folded up like that. Whenever you need a bag, start by taking a triangle and untucking the loose end. Hold the bag by this edge and shake until it comes completely undone. Depending on how tightly you wound the bag, you may need to put some elbow grease into it.

Tying a Knot

Fold your bag lengthwise. Turn your bag into a narrow strip for you to tie into a knot. How you orient its handles is not important for this method. To fold your bag: Smooth your bag out onto a hard, flat surface. Run your hands over the bag to remove as much air as possible. The flatter you make your bag, the smaller your finished knot will be. Fold your bag in half lengthwise to form a rectangle. Smooth and flatten as before. Fold your bag in half lengthwise again. It should once more form a rectangle, this time with a more narrow width. Keep folding the bag in half lengthwise until the layers are thick enough that you begin to feel some resistance. Make sure to flatten with each fold.

Fold your bag widthwise. Fold the strip in half along its width to make a shorter strip. You should now have a thin rectangle that is about half as long as your bag is tall. Test the flexibility of your strip by wrapping it around your fingers. If it's too stiff to do that, it will be too stiff to tie a knot with. Unfold the width crease and one or two length creases. Fold your strip back widthwise and test it again.

Make a small loop using your strip. Position the loop about 1 inch (2.5 cm) from the folded end of the strip. The loop should be just big enough for two of your fingers to fit through. Make sure that the folded end of the strip is in front, while the longer uneven tail that includes the handles crosses behind. The loop is the first step in tying what will be similar to a repeated overhand knot. If you have difficulty working with the strip because it's too short, you can always undo the widthwise fold. However, your knot will not be as compact or easy to undo.

Thread the tail overtop and through the loop. Take the uneven tail in one hand and bring it inward across the half of the strip closest to the folded end. Stick the tail through the loop and pull it through to the other side. Do not pull the ends to tighten the knot, yet.

Thread both ends through the loop. Start by bringing the tail back around and through the loop a few more times until you run out of length. Tuck the end into the center of the knot. Repeat this process with the remaining free end, pushing it through the loop to add to the ball. Once you reach the end, tighten the loop by holding the ball and tugging the free end. Make sure you're wrapping the plastic bag in on itself in one big ball of a knot. You do not want to make a separate knot over the first, as this will be a double knot. Double knots are harder to undo.

Undo the bag for use. You can't use a balled-up bag to hold anything. To unravel a bag, press a thumb through the middle of the loop in the opposite direction the folded end was wrapped. The knot should loosen and the folded end will pop out of the loop. Unravel one half of the knot. Do this again for the tail end, and your bag is ready to use. The knotted ball will not be nearly as neat and aesthetically pleasing as a folded triangle. Instead of displaying these bags, simply place them in a bucket or bag caddy until you need one.