Difference between scaling and doubling the size of a bezier path... Scaling actually distorts the size of the shape's border.

C4WorkSpace.m

@implementation C4WorkSpace {
    C4Shape *s, *t;
}

-(void)setup {
    s = [C4Shape rect:CGRectMake(20, 20, 100, 100)];
    [self.canvas addShape:s];

    t = [C4Shape rect:CGRectMake(400, 20, 100, 100)];
    [self.canvas addShape:t];

    [self runMethod:@"test" afterDelay:1.0f];
}

-(void)test {
    s.shapeLayer.affineTransform = CGAffineTransformMakeScale(2, 2);
    s.origin = CGPointMake(20,20);

    CGRect newFrame = t.frame;
    newFrame.size.width *= 2;
    newFrame.size.height *= 2;
    [t rect:newFrame];
}
@end