What's new
By:
Photoshop Gurus Forum

Welcome to Photoshop Gurus forum. Register a free account today to become a member! It's completely free. Once signed in, you'll enjoy an ad-free experience and be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Need Help with Knockout Blending


R

Rich54

Guru
Messages
1,914
Likes
3,714
I've just discovered the existence of the Knockout feature in the Layer Blending Options. If you select Deep Knockout it allows your current layer to bypass all intermediate layers below it and instead blend only with the original, bottom Background layer.

I tried a few experiments and got Deep Knockout to work, but it only seems to work if the original background layer is present and intact. If I delete or rename the background layer, or substitute something else as my bottom layer, the Deep Knockout doesn't recognize this new bottom layer as the "Background" and drills right past it down to emptiness---an entire screen of blank pixels.

How do I take the bottom-most layer of my stack and redefine it as a Background, so that Deep Knockout will recognize it? (Also, I've never understood why Photoshop even bothers with the background layer, what special properties it has, and what advantage it provides vesus any other "normal" layer that sits at the bottom of the stack.)

Thanks
 
When you create or change to a new background, highlight the new layer, go to LAYER > NEW > LAYER FROM BACKGROUND.

edit: Provided there is not an existing background layer. If there is, drag the lock icon from the BG you do not want to the trash bin icon (delete layer).
 
Last edited:
Thanks, now I can create/change the background layer. But do you know why Photoshop went to the trouble of making the background layer different from all other layers? I can think of several things you can't do to a background layer, but I can't think of any benefits from the background layer being special. What's good about it?
 
Rich, I really don't have a good answer for your question. Most images opened in Ps are locked as a BG. The BG is not technically a layer. A lot of the formats we use do not support things like effects and transparency like a jpeg for instance, so it needs to be altered into a working layer or just have working layers above it. This is a way of protecting the original image data in a sense. I personally just duplicate the BG and turn the original off, all of my work will build on the duplicate. There may come a day when all formats support editing and we will no longer need the BG in Ps.
 
Back
Top