In this step we're going to add a contrail to our plane. We're going to draw this contrail with a special clouds brush.
The Realistic Clouds tutorial shows how to make a clouds brush in case you're interested to know how to make one. In this tutorial we're going to use the clouds brush that was created in that specific tutorial.

You can download this clouds brush here (right click and select Save Target As...)

Look at the following screenshot:

Select the Brush Tool and click on the button in the options bar marked with A in the screenshot.
In the window that opens click on the button with the little black triangle(B) and then select Load Brushes... or Replace Brushes... (C)
What's the difference between the two?

Load Brushes:	add the new brushes to the existing brushes in Photoshop
Replace Brushes:	replace the existing brushes in Photoshop

Which option to use is all up to you, but my advice is to select Load Brushes...
Select the brush that you downloaded earlier and click on load.

Activate the brush by selecting it in the Brush Preset picker window that you opened earlier by clicking on the button in the options bar marked A in the above screenshot . You can find the clouds brush all the way at the bottom of the list of available brushes.

Enter the value 7 for Master Diameter (D). Make sure that the Opacity (E) for the brush is set to 100%.

Click on the Create a new layer icon in the layers palette to create a new layer.
Press the letter D on your keyboard to make your fore- and background color black and white:
Click on the foreground color in your toolbar...

...to open the Color Picker window.

Enter the value DDDDDD (light gray) in the box marked with A and click on OK:

 

Now let's draw the contrail:

• hold down the shift key until I tell you to release it (this will help us to draw a perfect straight line)
• move your mouse cursor to the center of the left side of your image
• press the mouse key but don't release it yet.
• move your cursor to the other side on the right (this will draw the actual contrail)
• release mouse key
• release the shift key

 

Add a layer mask to our contrail layer by clicking on the Add layer mask at the bottom of the layers palette.
Press the letter D on your keyboard to make your foreground color white and your background color black:

Select the Gradient Tool in the tool bar. (if you can't see it; it's under the Paint Bucket tool )
Make sure that in the option bar the Linear Gradient is selected and make sure the other settings are the same as in this screenshot:

With the mask still active (double border), hold down the shift key and draw a gradient from the left edge of the mask all the way to the right edge of this same mask (it's the same technique we used to draw the contrail).
Release the shift key again when you're done.
Note: we needed to use the shift key to draw a gradient under a perfect straight angle.

Next click on the layer mask and drag/drop it on the Delete Layer icon (soon you will understand why we remove the mask that we just created):

Photoshop will now ask whether you want to apply the mask before removing it. Select Apply:

So the reason why we removed the mask is to actually apply it to the contrail layer. Maybe a strange way to do things, but an effective way nevertheless.

Now that we've removed the layer mask, we're able to add the same layer mask that is already attached to our plane layer; with the contrail layer active (again, notice the double border), click on the plane's mask and drag/drop it on the Add layer mask icon .

 

Only for Photoshop CS2 users The above steps needed to duplicate a mask don't work in Photoshop CS2. The right way to copy the mask in Photoshop CS2: Make sure that Layer 1 is the active layer Hold down the Alt key (Option key on the Mac) Click on the plane's mask and drag it to layer Layer 1 Release the Alt key (Option key on the Mac)

 

Continue by changing the opacity of this layer to 70% (A):

We had to copy the mask, because our contrail will have to act the same way as our plane does (like we saw at the end of the previous page), otherwise we would have an odd animation in which the contrail would always stay behind the brightest white clouds.
Note: there is no need to remove the link symbol between the contrail layer and the mask we just copied, because there isn't one. It turns out that Photoshop only adds the link symbol if you create a new mask from scratch.

Click on the plane thumbnail in the layers palette to make the plane layer active (it will have a double border at A in the next screenshot) and select the move tool in the tool bar.

Move the plane out of the clouds and to the left side of our image with the same amount of space between the plane and the upper and bottom edge of the image.

Select the contrail layer by clicking on the contrail thumbnail in the layers palette and move the contrail just behind the left engine of the airplane (leave some space between the engine and the contrail).
Once the contrail is in the right position, click inside the area marked with the arrow (B) to link the contrail layer with the plane layer (a link icon will appear in that location):

 

Only for Photoshop CS2 users Adobe has changed the way we link layers in Photoshop CS2. If you use Photoshop CS2 you need to click on the contrail thumbnail first, hold down the shift key and then click on the plane thumbnail in the layers palette. After releasing the shift you have to continue by clicking on the link icon at the left bottom of the layers palette (A); the layers will then be linked, confirmed by the two link icons that appear in the layers palette (B). Continue by clicking once on the contrail layer to make it the active layer (it will now have a double border):

Both layers are now linked, meaning that the contrail will now follow the plane from right to left and that's exactly what we need for our animation.

Make sure that the move tool is activated. Move the plane all the way to the right and stop until you see only the front of the plane:

Hold down the shift key and press the cursor right key on your keyboard a few times until the plane has totally disappeared.

Save your current file by selecting in the menu File / Save

Continue on the next page where we will make this plane fly through the clouds.