I modified @Orion3DStudios “Easy Print Glider” to be larger, while maintaining a combination of lightness and structural rigidity. I also made some adjustments to the leading edge of the wings and increased the elevator angle, which I found to improve its gliding characteristics.

                                                                   See It In Action!

Hand Tossed

Dropped from an RC plane

Dropped from an RC helicopter

Pulled behind an RC plane

I included the Fusion 360 source file and a STEP file if you want to modify further.

I found using these print settings gave me a good balance of light weight and durability:

• 0.5mm line width
• First layer set to 0.1mm
• Other layers 0.2mm
• 2 bottom layers
• 3 top layers
• Rectilinear infill, 7%
• Monotonic line top and bottom fill
• 1 wall

Printed with PLA+, which gives a good combination of stiffness and durability. I believe PETG may be too flexible for this.

Note: you need to add nose weight to the plane for it to glide. This will vary depending on how you print the plane. For mine, I needed 8.5 grams of nose weight and my plane weighs 36.3 grams total. I used an M5 bolt and multiple nuts for the weight. You can also use fishing weights, heavy putty or any dense material that can be securely attached.