How to scale corner radius based on a logarithmic scale

October 29, 2007 2:58 PM

Is there a method that exists for defining corner radius on a drawn box in Illustrator which scales proportionality based on a logarithmic scale that is directly related to the size of the box.

As the marketing administrator for a small co-op here in TN, I am outlining a few design standards for marketing materials we develop. The most vexing standard is defining the method for determining a corner radius on a object, that when scaled, does not look over done or two large.

We are working primarily in Adobe Illustrator using the rounded corner effect with scale strokes and effects enabled in the transform palette.

It would seam to be an easy task of saying "all corners should be 4% of the longest side". Or even adding the length to the width, dividing that by 2 (thus giving an average) and then multiply that by .04 (4%). This works ok up to a point, but as the object gets larger, the corners become disproportionately large and do not look right.

I have come up with a few methods that are ok, but not great. The most effective is to have the designer always start with a 2" square, round the corners by .18" and then scale the box. Generally this works well unless the object is scaled to a full 8.5 x 11 sheet as a background, and then the corners look strange.

I am willing to use a chart of some kind as we use the rounded corner effect minimally but it needs to be more exact for the sake of keeping everyone on the same page.

Thanks for your help!

posted by tmgstudio to media & arts (4 comments total)

I have had some of these types of issues in the past as well.. since you are working in illustrator its a bit easier to fix the corners after they have been made. I think your idea for a chart is best. For a box of X size, use Z corner ration... for D size, use Y corner ration. then of course you would have to decide to the other boxs round up or down if they are larger or small than your pre determined chat size box...

or, 4% of all Boxes under X size, after X sixe (like 8.5 x 11) you simply use a set ratio... hmmm dunno if this help, but i feel your pain!
posted by crewshell at 3:09 PM on October 29, 2007

umm I guess I do not know how to use the R key....
posted by crewshell at 3:10 PM on October 29, 2007

Thanks for the insight. I did some more testing since I posted this. There seems to be a corilation between the size of the document and the size of the object. The method of adding one side of length to one side of width and dividing by 2 then multiplying by 4% works well up until the object is more than 60 % of the document size and then it has to be lowered to 3%.

I guess now I am wondering if all of this is too much. But when I am standing at the proof board looking at 10 different design pieces and I see one element that just jumps out at me as wrong, how do you tell the designer it is "wrong". Much of this is just gut feeling so I am trying to find the not so subjective way of handling it, lol.
posted by tmgstudio at 4:08 PM on October 29, 2007

what about just having a few different sized samples(ie: 2", 6", 12" with corresponding stroke and corner radius) that can be scaled to different sizes. Usually brand style guides are really specific about this sort of stuff so you could give them 3 or 4 different sized boxes to work with--in my experience the corners look ok when scaled a bit, but not a lot--assuming that your designers are using Illustrator.
posted by beckish at 7:59 PM on October 29, 2007