No cutting! No tape! Uses Letter-size (8½"×11") paper!
I had trouble finding instructions for a strong paper funnel that locks its sides together without the need for tape. I didn't want to require anything but a single sheet of paper. It's easy! And, I introduce some basic origami concepts, but I hopefully explain them adequately to make the folding go smoothly.
Step 1: Fold the Paper in Half Length-wise.
•Designed for one 8½ × 11 inch sheet of paper.
•The side folded into the center will not be seen either inside or outside the funnel.
• Standard origami notation has a regular dashed line mean a "valley fold", where you fold the paper toward you.
Step 2: Choose the Size of the Opening at the Bottom, and Choose the Width of Your Cone.
•The top shows a standard width funnel with a small opening.
•The middle is for a narrower funnel with a wider opening.
•The bottom makes a closed cup, suitable for holding larger dry goods, like candy or snacks. NOT LIQUIDS! I wonder if sand would run out like an hourglass? I thought, at first, it would be a closed cup, like for a snow cone. Boy was I wrong! Liquid drips right out the bottom without hesitation.
•Don’t forget to keep the long edges at the top, and the fold at the bottom.
•A light fold down the middle can help align your sides, until you get the feel for it.
Step 3: Fold Up the Sides, Overlapping Them.
•The illustration shows the top funnel shape from the 3 choices in the previous slide.
•It doesn’t matter which side is folded first.
Step 4: Fold Down Both Top Flaps Toward You, Matching the Back Edge.
•Yup, fold both flaps toward you.
•The bottom illustrations are the front and back once you’re done with this step.
Step 5: Open the Funnel and Flatten the Opposite Points Together.
•This illustration labels each of the four top points a, b, c, & d.
•The idea here is to spread apart the middle and bring together corners a & b to form corners c & d.
•This step also introduces the dot-dash line, or a "mountain fold", where you fold the paper away from you.
Step 6: Fold Down the Points to Lock the Top Edge.
•Fold a toward you, and b away from you.
•There are quite a few layers of paper, don’t worry about crisp folds.
•The funnel should feel very sturdy now.
•Finished height is about 4 inches, with a 3-inch diameter.
Step 7: Done! Round the Lip Into a Cone Shape and It’s Ready to Use.
An awful rendering in Powerpoint.
The narrow-opening funnel in action.
A look through the wide-opening funnel.