Vector Graphic Sizing

[Mateomono]

Hi,
I am designing simple vector graphics in Illustrator for a book layout. There is a specific size that they need to be, but I was wondering if it’s necessary to design them at 1.5x or 2x the size. I read that somewhere but am not sure if this is relevant to my project.

Thank you!

[Ton Frederiks]

Vector graphics are resolution independend. You can always scale them to any size needed without losing quality.

[Monika Gause]

If the graphics will be scaled down in the final lyout, you have to be very careful with stroke weights. Take care that those strokes do not get too thin for printing.