Using the Knockout Group setting without a group
Video: Using the Knockout Group setting without a groupIn the previous movie we learned what the Knockout Group setting does inside of the Transparency panel, this setting right here, and we know that we can only apply that to a group. Well let's modify that somewhat. We can actually fool Illustrator to think that we're working with a group even though we don't actually have a group in front of us. A group basically has multiple objects. Normally the only way that Illustrator kind of thinks about multiple objects is when you put them all together in the same group. But we also know that Illustrator has the ability to apply multiple fills or multiple strokes to a single object and we can tell Illustrator to treat those multiple fills or multiple strokes as multiple objects within a group.
- Next steps
Viewers: in countries Watching now:
In this installment of Illustrator Insider Training, Mordy Golding shows experienced Illustrator users how to create transparency effects and ensure reliable printing results. This course reviews the history of vector transparency and covers features such as knockout groups, opacity masks, and transparency flattening. Mordy also shows how to establish a safe workflow when placing Illustrator graphics containing transparency in PostScript, PDF, and InDesign files. A free worksheet is included with the course.
- Understanding how transparency works across the Adobe applications
- Deconstructing the Transparency panel
- Adding transparency to gradients
- Understanding how overprints and knockouts work
- Using a gradient or complex appearance as an opacity mask
- The rules of transparency flattening
- Working with complex regions
- Understanding the relationship between flattening and stacking order
- Creating and sharing flattener presets
- Saving PDF files and using the PDF/X standards
Using the Knockout Group setting without a group
In the previous movie we learned what the Knockout Group setting does inside of the Transparency panel, this setting right here, and we know that we can only apply that to a group. Well let's modify that somewhat. We can actually fool Illustrator to think that we're working with a group even though we don't actually have a group in front of us. A group basically has multiple objects. Normally the only way that Illustrator kind of thinks about multiple objects is when you put them all together in the same group. But we also know that Illustrator has the ability to apply multiple fills or multiple strokes to a single object and we can tell Illustrator to treat those multiple fills or multiple strokes as multiple objects within a group.
Let's see how we can use both that concept and the Knockout Group setting of the Transparency panel to solve everyday problems inside of Illustrator. Let's take this file here as an example. That's called strokes.ai and I have two strokes that are right here. Notice if I go into Outline mode, they are just kind of straight strokes that kind of zip right through my document. However, if I go back now into the Preview mode, I can select just this shape for example and it looks like it's a squiggly line but that's because it has the zigzag effect applied to it.
Now, I'm going to show you also that this object has two strokes applied to it. it has a 6-point dashed black stroke that appears at the bottom and it also has a 4-point white solid stroke that appears on top of it and this gives me the appearance of like stitching. If you're in the apparel industry and sometimes you actually create artwork where you want to draw a sketch of what a garment might look like, you might need to indicate where stitching is going to go. Now, this is actually a great example of how you might be able to use multiple strokes to solve an everyday problem.
You actually can use two stroke attributes on a single path and you now get the appearance of like a double stitched line. However, if you focus just on this area right here, because I've told the top stroke to be white, it kind of looks pretty natural on a white background. But as soon as I start to have this stroke kind of start appearing over either images or other colors or a pattern in this case over here, it looks wrong because the middle area should really be transparent. The middle area shouldn't be filled white. It should be whatever the color of the background is.
So I can't necessarily anticipate exactly what the background color is going to be in every case. Sure, if I know my entire garment is going to be solid white, I can get away with this very easily. But more likely you have this artwork that maybe has different types of colors inside of it, clothing sometimes filled with patterns or with images, and this type of effect simply doesn't work. Well it might if we think about using the Knockout Group setting. Let's also take a look at this stroke that appears on top of this. If I click on this to select it, I'll see that I have three different strokes with a zigzag and that gives me the effect over here of these little circles that kind of go along a line.
It looks very nice over here where I have the white chainlink basically that I have going on over here, but the middle areas I really want those to be transparent. I want these circles to look hollow, and I don't want to see those settings that appear right over here. So while that looks really nice on a purple background, it doesn't look so nice when I start using other colors or images or patterns as the background for it. So how can I use the Knockout Group setting to make those areas transparent? Well, it's actually pretty simple. Let's see how to do that. I'm going to start off by working with a stroke here on the bottom and I click on this object right here to select it.
And I'm going to go to my white stroke right over here. I'm going to click on the triangle to twirl down so I can see the Opacity value just for this white stroke. I'm going to click on the Opacity here. I am going to change the Opacity of the white stroke to 0 and click OK. So right now what I've done is I've taken that white stroke. It exists, it's there, but I've told its Opacity to be completely 0. Next, I'm going to click on the word Path in my Appearance panel because I want to make sure that I am targeting the entire path and not just one of the strokes or one of the attributes of that element.
Next, I'll come over to the Transparency panel and I'm going to turn on the Knockout Group setting. Again, when I click on it the first, I'm going to see the neutral setting, but if I click on it the second time, now what happens is that I now can see completely transparent all the way through the middle part of the stroke, and let's understand exactly why this just happened. I told Illustrator to use the Knockout Group setting for this path. This path has two strokes inside of it. The topmost stroke has an Opacity value applied to it, which because the Knockout Group setting is on treats the two strokes as two objects in a group and the top object, which is the top stroke in this case, knocks out the stroke that appears beneath it.
So now I get a true transparent setting through the middle part of that stroke. Let's see if we can actually apply that to this shape as well. I'm going to select the top stroke right here and with the part that we want to be transparent is actually this purple shape right here. We want those parts of the circles to be completely transparent. So I'm going to change the Opacity value of just this one stroke to 0. Next, I'll target the entire path and I will come to the Transparency panel and click once on Knockout Group to turn it to the neutral setting and then click a second time and now I specified that middle area right now as completely transparent.
So now I can see through that part over here to the pattern beneath it or to the image that appears inside of this file or to any other color that stroke may overlap. So we've done two things here. First of all we've treated a single path as a group. We did that because the path itself has multiple attributes inside of it. So we're treating for example in this case here three strokes as if there were three objects inside of a group. Next, we're using the Knockout Group setting to actually take one of those objects and have them knock out the objects that appear beneath it.
So we can see now that this technical setting, Knockout Group, can be very valuable in solving everyday problems in Illustrator.
There are currently no FAQs about Illustrator Insider Training: Seeing Through Transparency.