How to easily assemble an envelope

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 assemble an envelope
assemble an envelope

 

Image Source: vk.com

To make this easier, it’s possible to draw another vertical line that is parallel to the vertical lines and will pass through the center of the square. Align the axis (line of fold) of your template along this line.
Trace the template with pencil.

 assemble an envelope
assemble an envelope

 

Image Source: vk.com

5) Cut the heart out of cardboard.

 assemble an envelope
assemble an envelope

 

Image Source: vk.com

6) Fold the sides along the incision lines.

7) Fold the envelope.