Expert: LizaL - 12/21/2004

Question
oh i'm sorry. What I meant to ask was what the option intersect layer mask means in photoshop cs itself.

-Thank you-
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Followup To
Question -
could you clarify what intersect layer means?
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Followup To
Question -
i have a picture of a branch and i am trying to place a opaque gradiant only on a leaf itself using masks. How do I do this? Please help. I have been trying for so long?
Answer -
Hi Adam,

Try one of these techniques:

Technique 1, using Quick Mask:

1. Near the bottom of your tools palette are two buttons that each have a circle in them. These two buttons appear just below your color swatches. Double-click on the one on the right to enter Quick Mask mode.

2. You'll see a dialog box that says Selected Areas -- this is the one you want to tick.

3. Select a brush from your tool palette, and using this brush, paint the leaf you plan to put the gradient fill in.

4. When you're finished, exit Quick Mask mode by clicking on the left-most button below the color swatches (the one beside the Enter Quick Mask mode button).

5. You'll have an empty selection then, and of course you could go ahead and apply your gradient to this selection. But I usually go to the layers pulldown menu and select New Layer Via Copy, so my selection will be on its own layer. That way if I change my mind about it, I can always go back and delete it without messing up the original picture.

6. If you make a new layer, you'll need to make sure that layer is selected, then go to the Select pulldown menu and choose Load Selection to activate it. Then apply your gradient.

Watch this little movie -- it might make things clearer:

http://little-works.com/all_experts/quickmask2.mov


Technique 2, using the Pen Tool:


1. It's pretty much the same as using Quick Mask, except with the pen tool, you can really get in there and make a tight selection, and have more precision than with Quick Mask. But they don't call it "Quick Mask" for nothing, LOL!

Anyway, to do this, first choose the pen tool and trace around the leaf that you want to have the gradient fill.

2. Now go to the Paths palette, and you should see a preview icon in that palette that says Work Path. On the top left of that palette, click on the little arrow at the top of the Paths palette. You'll see Make Selection as one of the choices below, and that's what you want to choose. This will activate the path you just created as a selection. You can also feather your selection at this point, as you'll be presented with a dialog box to that effect.

If you find you have an active selection not only around your leaf but around your whole image, go to the Select pulldown menu and choose Inverse. That'll make it so only your leaf is the active selection.

3. Still keeping the selection of the leaf active, click back on your Layers palette, and from the Layers pulldown menu, select New Layer Via Copy. This will put your leaf path on its own layer.

4. Now apply the gradient, using the gradient tool, on that leaf selection only. If you have to re-activate the selection, hold down your Command (for a Mac) or your Alt (for PC) key and click on the layer that holds the leaf path.

Hope this helps! Let me know how it works out, and if I need to give you more advice, I'll be glad to.

Lisa
Answer -
Hi Adam,

I'm not sure I know what you mean -- I don't think I used that term ("intersect layers"). Can't find it anywhere in my answer, anyway.

But did you maybe mean where I mentioned Inverse? That would be if you selected a part of a picture, then selected Inverse, which would reverse the selection.

Now that's a really confusing way to explain it, sorry! Look at this and hopefully it'll make it clearer.

http://little-works.com/all_experts/inverse.mov

(This movie loaded slowly for me; you might have to give it a couple of minutes. It's not that big, but I might have too much on my server.)

When I select the picture of the man, he's the only thing selected. When I go to Inverse, under the Select pulldown menu, suddenly you see the whole picture's boundaries selected, right along with the original selection of the man. If I were to Cut at that point, the rest of the picture is cut, and only the oval selection remains.

Did this answer your question? If not, please don't hesitate to post back and tell me where I need to be more clear.


Lisa

Answer
Hi again Adam,

Got it! After I thought it about, I figured you might be referring to that.


You can do several things in terms of intersecting masks and selections in Photoshop.

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Watch this movie to see about intersecting channels:

http://little-works.com/all_experts/intersect.mov


1. I made a selection around the wheat with the lasso tool. I saved this selection and named it "shape," and any time you save a selection, it becomes a new channel. And a channel is a mask, too, which is something to keep in mind.

2. Then I made another selection on another part of the picture, this time with the rectangular marquee tool.

3. I made sure the little button on the far right at the top of the options bar was depressed. This is the intersect selection option. Doing this ensures that the next selection I make will intersect with the saved channel.

4. When you intersect channels, or masks, like that, essentially Photoshop calculates the difference between the two selection measurements and produces a new channel, or selection. So that's the skinny on intersecting channels, or masks.


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This second method is simpler because you don't create new channels. You could consider this just a method of altering an existing selection.

http://little-works.com/all_experts/intersect2.mov

In it, I've selected part of the dog's ear, and then I select the marquee tool. Making sure I have that little options box checked (at the top of the screen, as before), I just drag over the existing selection. This is a quick way of doing what I did in the first example, and you don't have to save anything as a mask.

But of course, if you have an image that requires a mask, you'd want to use the first option so you could save it as a new channel.


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If you're using the Shape tools, you can combine those with that same intersect method. Draw with any of the shape tools, then choose that little intersect button before you draw a new shape. This will restrict the new shape to the area of the interesection of the new area, and the existing area. So what you're doing is actually making more than one shape on a layer, and combining (intersecting) those shapes.

Like so:
http://little-works.com/all_experts/intersect3.mov


Hope this answers your question! If not, please post back and let me know.

Lisa