Wires Tutorial Redux: Knockout Layers

This tutorial seeks to emulate the effect generated by my Wires and Splines Tutorial using a SIGNIFICANTLY REDUCED method. Where my previous technique involved multiple copying and pasting events to render layer-styles on individual layers and then merge them down, this technique will use three layers total, no copying and pasting required! In my experience, mastering this technique reduces interweaving-layer production time by at least half.

Wires Tutorial – ELEGANTLY USING KNOCKOUT LAYERS

This tutorial seeks to emulate the effect generated by my Wires and Splines Tutorial using a SIGNIFICANTLY REDUCED method. Where my previous technique involved multiple copying and pasting events to render layer-styles on individual layers and then merge them down, this technique will use three layers total, no copying and pasting required! In my experience, mastering this technique reduces interweaving-layer production time by at least half.

In short, here are the advantages to this technique over the older tutorial:

• Very simple method using just three layers.
• All layerstyles preserved.
• No bizarre copying, rasterizing, and erasing.

Difficulty

Easy to Intermediate. Despite the more complicated concept of Knockout Layers, this tutorial will walk you step-by-step through the process, providing graphical milestones to check your progress as well as providing all the short-cut keys so that you can find your inner power-user.

Although it looks like a lot of steps, it goes quickly, especially when practiced. It may take 10-20 minutes to do it initially, but stick with it and you can easily cut that time down to 1-2 minutes, even for complicated projects.

Requirements

• Photoshop version 7.0+ – I designed this tutorial using Photoshop CS3 on an MacBook Pro, but it has been successfully replicated using Photoshop 7.0 on a PowerBook G4.
• Photoshop Layers palette – Make sure it is open and accessible (F7 to toggle it in Photoshop CS3).

Making the Thick Tube

For this tutorial, the goal is to create a thick tube, and then a skinny wire that will realistically wrap around it. Let’s start by making the thick tube.

1. Start by opening Photoshop creating a new document (Ctrl/Cmd-N).
   • In this example I created a 300 pixel by 300 pixel image area with transparent background.
2. In your Layers Palette select the default layer (should be the only one there in a new document). I renamed mine “Thick Tube” for clarity.
3. Select your Brush Tool (”B“ is the shortcut key) and select a nice round, solid brush.
   • Make sure it’s not the Pencil Tool that you’ve selected (you can toggle between the two by pressing “Shift+B“).
   • Make sure the Brush Opacity and Brush Flow are set to 100%. I used a round brush with a diameter of 90 pixels in this example.
   • Set the active color to whatever you desire.
4. Brush in your tube however you wish it to look.
   • I “altered” my brush a little bit by entering the Brush Palette and decreasing the Brush Spacing to about 4%. This represents how frequently Photoshop paints a circle to draw your line. A High number would end up with a string of large dots, whereas a small number results in a smoother line.

Making the Skinny Wire

Here, we’re essentially going to replicate what we did above, only on a new layer and using a smaller brush.

1. Create a new layer in the Layer Palette by hitting the New Layer button at the bottom of the palette. Move the layer above the Thick Tube layer and name it something useful, like “Skinny Wire”.
   • Alternatively, press Ctrl+Alt+Shift+“N”/Cmd+Option+Shift+“N” to create the new layer.
2. Click the Skinny Wire layer to select it, then activate your Brush Tool (”B“).
3. Select a smaller brush and paint your wire onto the new layer.
   • I used a round brush with a diameter of 9 pixels, with a different color.
4. Apply the following Layerstyles to each layer:

At this point you should have some kind of thinner wire laying over the top of the thick tube.

• Now add the following layerstyles to the Thick Tube:
  • 
• Now add the following layerstyles to the Skinny Wire:
  • 

Hopefully you’ve got something moderately pretty, like the below example:

Knocking Out

Here’s where the magic happens. Essentially we create another layer, group it with the Skinny Wire layer, and tell it via layer-styles to selectively erase the Skinny Wire, but leaving it’s layer-styles unaffected. Here’s how it works:

1. Create a new layer group by pressing the New Layer Group Button at the bottom of the Layers palette.
   • I called mine “Wire Knockout“.
   • 
2. Drag the Skinny Wire layer inside the Wire Knockout layer group.
3. Create a new layer (Ctrl+Alt+Shift+“N”) and drag it into the Wire Knockout layer group ABOVE the Skinny Wire layer. Name it “Knockout“.
   • 
4. Create a selection of the Thick Tube by Ctrl/Cmd+clicking the thumbnail for the Thick Tube layer in the layer palette.
   • 
5. Select the Knockout layer by clicking on it, and then use the Paintbrush tool to paint over the areas you want the Skinny Wire to disappear beneath the Thick Tube.
   • 
6. Now edit the Layerstyle for the Knockout layer by double-clicking on the layer in the Layers Palette.
   • 
   • On the Blending Options panel, set the Fill Opacity to 0%.
   • On the same panel set the Knockout drop-down box to Shallow.

You should now have something similar to the next image, in which areas that you paint on the Knockout layer cause portions of the Skinny Wire layer to disappear while respecting the Skinny Wire‘s layerstyles!

OPTIONAL: Additional Shading

I like to take the technique a step further by adding some free-hand shadowing from the Skinny Wire over the Thick Tube, and vice-versa (depending on what’s overlapping what_. Here’s how I do it.

1. Create another layer above everything else and call it “Shadowing”.
2. This sequence of selections is complicated, so PAY ATTENTION!
   • Ctrl+Click the Thick Tube layer’s thumbnail to create a selection based on that layer’s contents.
     • 
   • Ctrl+Alt+Click the Skinny Wire layer’s thumbnail to remove that layer’s contents from the selection.
     • 
   • Ctrl+Shift+Click the Knockout layer to add the knocked out portion back to the selection.
     • 
3. By now you should have a selection that should exactly trace the Thick Tube except for the visible portions of the Skinny Wire. Use your Paintbrush/Airbrush tool to add some darkening underneath the Skinny Wire to add some dimension, like it really is floating over the Thick Tube at parts.
   • 
4. We can do the same for the Skinny Wire on the same or a different layer. Here’s how to make the selection:
   • Ctrl+Click The Skinny Wire layer’s thumbnail to generate a selection based on its contents.
   • Ctrl+Alt+Click the Knockout layer’s thumbnail to remove its contents from the selection area.
5. Bust out your brush tools and start shadowing the Skinny Wire to add some further dimension.
   • 

That’s it! Here’s how the final render should look:

Please feel free to comment if you get stuck, have questions, or feel that I have omitted something! :)