Small notches on the corners help you place the stencil better.
 
Depending on how large the paper you choose is, the protruding foil fixes the paper on the base.
 
Square
- Theouter frame is approx. 2.25 cm wide. 
External dimensions: 19.5 cm x 19.5 cm
Internal dimensions: 15 cm x 15 cm
- Theinner frame is approx. 2 cm wide.
External dimensions: 14 cm x 14 cm
Internal dimensions: 10 cm x 10 cm
 
Please the Instructions Be sure to read through when using the plain colored stencil. 
 
The self-adhesive stencils are designed and manufactured in every detail by Schlichtbunt.
 
Photo source: Plain Colorful
Errors excepted!