# Why these two shapes behave differently when scaled up using align to pixel grid?

See image 1 below.

• Orange shape has a width of 38px and a thickness of 1px, with a radius of 12px
• Green has a width of 152px and a thickness of 1px, with a radius of 3px

I created these shapes using the technique in image 4.

There are two rectangles one over the other, and I used the `MINUS FRONT` Pathfinder command to create these two shapes of the same height but different widths and radii.

My problem occurs when I try to enlarge these shapes.

Behavior 1 (image 2): I enlarged each of them individually to 200%. The green shape maintained a correct thickness (2px) but radius got distorted, and the shape became a straight line. The orange shape maintained every aspect.

Behavior 2 (image 3): When I enlarge both of the shapes together, both shapes maintained their proportions and nothing got distorted.

Why is that?

I need to maintain the pixel perfect ratio and enlarge without losing/distorting the radius. Is this something to do with the RADIUS / RADIUS-WIDTH RATIO?

Generally, is it even possible to maintain the proportions of such shapes given that align to pixel grid is checked?

• 1. what you call height is simply the thickness of the stroke, or the stroke itself (it's clear that the green shape is higher than the orange one). 2. did you finish the boolean operation (merge shape components) or is the shape you used to subtract still part of the objects? Oct 17, 2018 at 15:51
• another question: are you scaling just the height or width+height proportionally? Oct 17, 2018 at 15:57
• 3rd question: are you using photoshop or illustrator? you added both tags. I'll assume Illustrator. Oct 17, 2018 at 15:59
• I can't reproduce the problem Oct 22, 2018 at 8:54
• I tried to reproduce it too, but can't. May 10, 2020 at 8:48

Solution

Modify the inner curve or move the bottom point a pixel down:

• Hi, I can't move it a pixel down as I don't have to change radius. Further I was more interested in knowing the reason for this behavior. Aug 19, 2018 at 14:45