Suppose your model is created at a scale 1:1, “real size”. When you are going to print at say a scale 1:20 this action is going to reduce everything by a factor 20. This also means its textures are going to get scaled down during printing. Now suppose we want a texture that is 2cm wide on paper, printed at a scale 1:20. How large would the texture need to be in your model? Remember: printing will reduce textures by a factor of 20. That would result in 2cm/20 => 1mm on paper, which is NOT what we need.
So to correct and compensate for this effect Skalp will place such a texture scaled exactly 20 times larger inside a Skalp section defined at 1:20. If you would measure the tile size of the texture in your model you would find it to be 40cm. This is correct since printing this at 1:20 you would get 2cm on paper as expected. (40cm/20)
Printing a model at a certain scale can either be done right from inside SketchUp or from a referenced view of your model inside Layout. SketchUp printing is essentially limited to printing out scenes while the Layout option offers an impressive range of superb annotation features.