1

quick introduction to the problem.

Say I have an image on which I applied a layer mask and a black and white effect. (With a duplicate of the mask). Like so: enter image description here

If I change the canvas size (which happens alot vertically when designing for web), the black and white effect and the photo will show on all the new pixels created. (you can see on the mask panel on the right that all new pixels are white on the mask) enter image description here

My question is, is there a way around this? (a workaround would be to set the default fill of a mask to black when resizing. That way, the effects WOULDN'T be applied by default.Sadly, I haven't found anything of the sort in Photoshop's Preferences)

Am I using masks totally wrong? Maybe there's a better way to apply black and white to pictures in layout, I just haven't found it!

This might not seem like this much of a hassle at this scale, but when you have 15 different pictures on a page with black and white masks on them and you have to make the canvas bigger, it means that you'll have to manually go through 15 different masks to remove the black and white effect that has been applied to the new pixels.

Thanks alot!

  • I'm not entirely sure I understand. Could you fix the second image how you would like it to appear and post that as a third screenshot? – Ryan May 15 '15 at 19:22
  • @Ryan the user has placed the image at full size on the canvas. He uses a vector mask to clip the part he doesn't want to show. When the canvas gets expanded, the vector mask will show white and reveal the image. He is asking if he can expand the canvas and have the clipping colors by default be black. – AndrewH May 15 '15 at 19:24
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    I would use Clipping mask on that. – Joonas May 15 '15 at 19:49
3

When you create a layer mask there are two option... A mask set to Reveal All or a mask set to Hide all.

The difference is the initial color of the mask.. if it's a white mask, you've created a Reveal all mask. If it's a black mask, you've created a Hide All mask.

When you click the Add Mask button at the bottom of the Layers Panel it by default creates a Reveal All mask. This makes it a white layer mask and any current selections are made black. It starts with everything visible, then removes the selection from that area - allowing selection to be hidden.

If you were to hold the Option/Alt key down when you click the Add Mask button at the bottom of the Layers Panel it creates a Hide All mask. This means it starts with everything hidden and any current selection is made white - allowing the selection to show through.


Its important to understand the above information in order to answer your question.

When you create a Reveal All mask then move it around, the default color of the mask is white. So the areas off the canvas are white.... moving the layer around brings these white areas of the mask (visible areas) into view.

If you want the areas outside the canvas to be hidden you need to start with a Hide All mask. This way the default color of the mask is black and hides anything. Therefore moving the layer around will not show anything currently off the canvas.


It is very common for users to...

  • make a selection
  • click the Add Mask button
  • then invert the mask.

I would suggest rather than doing this, you get in the habit of

  • creating a selection
  • hold the Option/Alt key
  • click the Add Mask button.

This will solve this issue for you entirely and removes the need to invert the mask.

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    @Ryan, the menu has items you can assign shortcuts to Layer > Layer Mask then choose which mask you want. .. and you deleted your comment :) – Scott May 15 '15 at 19:44
  • Just tried making an action and it recorded that I held Alt down. Its why I deleted comment. Might still be useful to do Ctrl+I in this persons case since at least some of their files are already created. – Ryan May 15 '15 at 19:45
  • Inverting will only invert the visible area of the mask over the canvas. It will not change the default color of the mask. Only creating the mask as a "Hide all or "Reveal All" sets the default color of the mask. – Scott May 15 '15 at 19:46
  • It changes the Mask type. I never knew that until today but I just tried it and confirmed it. Give it a shot. Resize. Then undo invert and resize again. It'll change, promise. At least in CC. – Ryan May 15 '15 at 19:47
  • It depends a great deal on the size of the masked content. If the image being masked is entirely enclosed in the canvas, then inverting does appear to change the mask type. However, if the image is largely outside the canvas, depending upon how you create the mask, inverting after the mask is created may not work. So, in short, in some cases, yes inverting will work. In others it will not. – Scott May 15 '15 at 19:52
2

See Scott's answer for the correct answer to your question. However I want to add my answer as an alternative method to solving your issue which I think will be an easier way to manage your masks.

I would use a clipping mask (which is different than a vector mask you have applied to each layer) for the graphic. You can extend the base object past the canvas size. Once you widen the canvas, the object will still show up since the base layer was expanded past the original canvas.

So the first image will show the layer shape that will hold the image. See how it extends past the canvas.

placeholder layer

If I extend the canvas horizontally in both directions then I still have the shape layer shown (you can certainly make the base layer holding the graphic much wider than the canvas if you think you will expand that much).

extending the canvas size

You would place your graphic above your base layer and hold alt and left click between the 2 layers to create the clipping mask.

clipping mask

You will still have to fill the background layer when expanding the canvas but you won't have to redo the masks.

  • Hi Andrew, thanks for answering the question! As you said, what I was looking for was Scott's answer. However, I'm a bit curious as to why you prefer this method. Are there other advantages to this method? When is it best? (If you don't mind explaining, of course) I mostly use masks to apply various effects to/crop images in web layouts, and it would seem using a "hide all" mask on a folder containing the image and the adjustement layer would be ideal, but I'm always willing to learn. – Benjamin Smith May 19 '15 at 21:39
  • In your method, you have the full image. You mask the area you want to see with white. But how would you easily change that mask height or width? Sure you can use the marque tool to draw a new selection and use the paint brush to show the new mask but I think using a clipping mask is much more efficient. The only thing you would have to change is the base layer. You don't need to change any of the child layers at all since they are clipped by the base layer. It is much easier to use the transform tool to re-size the clipping area than using a vector mask on each layer. – AndrewH May 20 '15 at 14:22
  • Alright I understand! Indeed, cmd + T the shape to resize the clipping mask is probably faster than a mask. However, you may want to know, you can also apply a mask on a folder to re-create your "base layer". I usually put my image, and the adjustment layers that affect it inside a folder, and apply the mask on that folder. Always good to know different techniques though, thanks alot! – Benjamin Smith May 21 '15 at 16:14

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