I showed this trick to a colleague yesterday and he said it was too good not to pass along.
I do a lot of my 2D product exploration in Illustrator. I used to be a dyed in the wool Photoshop guy until Illustrator 10 came out. I realized most of what I was doing in Photoshop could be done in Illustrator with files that were about a tenth the size and without the need for some other drawing tool – like Vellum. For me it’s all about getting to excellent results quickly.
Along the way, I became obsessed with the appearance palette. I think it’s a totally underrated tool and I haven’t found much written about it, but the example I’m about to share starts to show what it can do. Actually, I’ll start with something it can’t do. Or, at least – doesn’t do very well…
Let’s start with a square. Nothing special.
Next, go to Effects > Stylize > Round Corners. A predictable result.
But what about non-rectilinear shapes? A more common scenario in product design.
I took the square and yanked some of the control handles around just to make something funky. I don’t think I would design a product that looked like this…
Here I add the same Effect and, like you, I’m scratching my head. Why do I get this? Clearly this is not what that shape should have looked like with rounded corners.
This has been broken since Adobe introduced the “Round Corners” feature. Even the less flexible and more destructive “Filter” version of this tool does the same thing. So clearly they are just re-using the same broken code. There isn’t really any predictable way of adding corner rounds to a shape in Illustrator. I’ve played with Hot Door’s CAD Tools and have had mixed success in these situations too. So here’s my work around…
Start with the shape and add a Path Offset effect. set it to a negative number equaling your desired radius. Here, it’s -10 points.
It should look something like this.
Now we are going to “stack” some effects. This can be done by either choosing the effect again from the effect menu, or by selecting it right in the Appearance palette and selecting duplicate in the fly-out menu, or (as I do) just drag the FX layer down to the new/duplicate icon in the palette. Double click the duplicated FX layer and change the offset value from negative to positive. Also change the Joins type from Mitered to Round and boom, you have perfect radii on your shape.
You can save this as a “Graphic Style” and access it any time from the Styles palette. One thing to note though…
Obviously, this is only useful if all your rounds are the same radii. If you want to have different radii on each corner, I use the Expand Object command on a duplicate shape, change the offset values to the second desired radius and expand again. A little snipping together of the shapes will get you to your result. You lose the “live effect” aspect of it, but it’s the most accurate way of getting that particular result.
Lastly, here’s an example of how obsessive I can be with the Appearance Palette. Here are some connectors I’ve rendered. These are part of a library I keep handy so I can quickly populate a product design with all the right bits. They don’t use the above technique in particular, but the ideas are largely the same.
Each connector is completely rendered from just 2 circles (as shown at the far left). The reason I do this is simple; back in the day, when I used a ton of shapes to render simple objects, not only would my files become heavy and difficult to manage but, later – when I’d export my ideas to a CAD application like Alias, all that garbage would come with it and I’d have to clean-up everything I had done just to make the rendering look nice. This way, rendering entirely with the Appearance Palette, my render only consists of the two circles I care about when I get to CAD. It saves a ton of time in the long run is and is generally just easier to deal with.
