Quick Tip – Use Layer Masks to Erase in Photoshop

Erase with MaskingWe’ve all had to work with photos that need to be cut down and have parts removed. Do you reach for the Eraser tool first? If so, you’re locking yourself in to changes.

Here’s a less destructive alternative using layer masks.


Erasing is Destructive

Sure, it may be nice for a quick fix, but erasing completely removes content from play. The only way to retrieve it is through backtracking the history panel or keeping the history brush handy.

But how many of us are perfect the first time? That’s the reason I like web design so much. Nobody will penalize you if mistakes are made at first. It’s your ability to fix them that matters.

Using the eraser makes it harder to go back and make changes after the fact. How do we get around this? The answer lies in layer masks.

Masks Just Hide the Content

Let’s use this picture I took last year of a flock of geese to demonstrate. The solid blue background will make removing the background much easier.

We’ll start by using the magic wand tool to select the sky background.

Masking Marquee

Ordinarily, pressing the delete key would take care of the background just fine. We want to avoid destructive erasing though. Instead, we’re going to take a couple more steps to make it easier. The goal for layer masks is to maintain as much of the original image as possible.


Before we can remove the background using masks, we have to switch the selection to the geese. Press ctrl-shift-I (cmd-shift-I for Macs) to invert the selection. Now that we’ve got the geese rounded up, it’s time to apply the layer mask.

With the geese layer selected, add a mask using the button below.

Add a mask

Photoshop will automatically mask according to the current.

Active Layer Mask

With layer masks, black is hidden and white is visible. Here’s a look at what the mask for the geese looks like:

Black and White Mask

Not bad! This is important because the background is still there. It’s just not visible. If you wanted to show the background, it would be a simple matter of adding more white to the layer mask in the appropriate area.

And that’s more or less it! Same effect, less commitment.

Complete Mask

Better Practice, Less Headache

Since I’ve gotten into the habit of favoring layer masks over the eraser, I’ve saved myself a lot of problems. If I accidentally deleted something I need, it’s not such a big setback, I’ll simply make it visible again.

Here’s a question for the crowd: Is there a time where using the eraser tool is more productive? Let us know what you think in the comments.

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About Zach Dunn

Zach is a partner and interface designer at One Mighty Roar from Massachusetts, USA. Follow him on Twitter @zachdunn.

 

Discussion

  1. Alex McCabe

    March 6th, 2009 at 4:51 AM

    Good tip. what happens if there are items in the background though, does that make it harder? are there any other ways of masking out items?

  2. Zach Dunn

    March 6th, 2009 at 9:13 AM

    @Alex

    Background items would certainly make things a little bit trickier, but the main point I’m trying to showcase is how using layer masks will be more forgiving when you make mistakes.

    My recommendation would be to use either the pen tool or marquee selection and trace roughly around the item you’d like to extract. Hide the rest with the layer mask, and then zoom in to fix the details.

  3. Ivo

    March 6th, 2009 at 12:33 PM

    Great tip ! Keep it up

  4. Petey Boy

    March 6th, 2009 at 2:26 PM

    Hey, great article. This is very helpful. The problem I’m having is playing with the mask after it is made. I want to add text to the mask so that the picture just comes through the text. How would I go about accomplishing this? Also, is there a way to feather the masking? maybe using a bezier curve? or am I making things too complicated when they don’t need to be?

  5. Zach Dunn

    March 6th, 2009 at 3:06 PM

    @Petey

    If you hold down the text tool icon, you’ll find that there is an additional option to write in marquee format. Once you’ve finished typing your words, you can use this selection to crop the photo behind it.

    You can feather the selection through the Select menu as usual, just make sure that you are within the layer mask before applying either blacks or whites. Give it a try, if you’re still lost let me know.

  6. KiwiPulse

    March 7th, 2009 at 10:44 AM

    Nice easy trick! Thanks :P

  7. Cristhian Bedon

    March 8th, 2009 at 7:40 PM

    Great tip, and I have been doing the same thing also.

  8. Heather Flyte

    March 15th, 2009 at 4:30 PM

    Layer Masks are the most wonderful thing in the world. And there are so many ways to use them. Painting on the layer mask is probably the way that has the most control. Most people that use Photoshop only use about 30% of its features, and I was that way until I started really using all the layer options (not just masks, but adjustment layers and clipping masks).I’ve been using masks so long that I only default to the erase when I’m in a huge rush. And even then, not that often.

  9. Callum Chapman

    March 28th, 2009 at 5:32 AM

    great post, is a really handy tip! I use to hate when I was new at photoshop many years ago and was cutting out photos.. I’d make a mistake and not realise then I’d have to do it all over again!

    Callum Chapman’s last blog post..Batch Image Resizing in Photoshop

  10. Art

    March 31st, 2009 at 6:30 PM

    Your right abt the sweet :) thx its good

    Art’s last blog post..Blasting Art Contest!!!

  11. Brochure Printing

    April 1st, 2009 at 7:30 PM

    Great tutorial! The technique you showed here is really good. Beginners will find this really useful and informative. Keep up the good work!

  12. Enk.

    May 6th, 2009 at 5:03 PM

    That was cool but I guess its easy to mask stuff from a solid color.. I thought there must be some easy tips for mix backgrounds too :$

    Thanks anways ! :)

    Enk.’s last blog post..30 Typographic Logos – Inspiration

  13. restauración fotográfico

    May 7th, 2009 at 11:04 AM

    Muy bueno! Ami me encanta este resulto.

  14. Vimal Saifudin

    July 16th, 2009 at 9:34 AM

    It really helped me because i was using the erase tool for so long.. Thanks for your post

  15. Arun M

    August 31st, 2009 at 5:44 AM

    Nice work. Thanks

  16. JP

    March 11th, 2010 at 1:34 AM

    This is very useful. However, some projects might require that the layer mask affect multiple layers while having the same exact shape. Is this possible? Or would you simply have to create two layer masks?

  17. Les

    July 5th, 2010 at 3:25 PM

    I don’t have Photoshop – I usually use Paint Shop Pro, more recently I installed GIMP which is more like Photoshop but open source (as in free) so does anyone else use GIMP and where can I find some decent tutorials to use it?

    For example, as with this article, to remove backgrounds as I use earse in PSP and the results are honking (!) most of the time.

    Thanks.

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