There are many ways to create Photoshop brushes. For example from scanned images, drawings or photos. In this tutorial I will show you how to create a brushes from a photo. This is a medium level of difficulty because you don't need to cut out the object, a cloud in this case, featured by a high contrast level. Once learned the technique you can apply it to about every photo you have.
The object needs to be sharp, neat and not overlapped with other things. Using a white or plain background for your photo is obviously better and easier than using a patterned background one.
Moreover, in order to have a high quality brushes you need to create it with the higher resolution you can. That's why when you use that brushes the resizing makes it blur. In Photoshop CS4 you can create brushes up to 2500x2500 px.
Open the photo which contains the object that you want brushezy. I've chose a sky photo to create a cloud brushes.
Photoshop uses gray scale info while defining brushes. Converting your document to Grayscale will give you a better control on of what you are doing.
Turn the photo in a grayscale method.
Open the Image > Adjustments > Levels panel. Play with Levels to reach the best contrast result by dragging the sliders in the Input Level panel.
IMPORTANT! Please note that because of, as we said, Photoshop brushes are defined on a gray scale, than everything that is 100% white disappears. White=Transparent
Black=Opaque
In this case to completely remove the background I go under Image > Adjustment > Invert
With my white brushes I still clean the background making it completely white.
Select the Crop Tool an set width to 2500px. Crop your image.
In order to avoid white areas in my cloud that will be transparent I've also adjusted Curves (Image > Adjustments > Curves panel)
Go to Edit > Define Brush Preset...
You will find now your new brush in the Brushes Palette
You can also save your set going to Edit > Preset Manager, choose Brushes as the Preset Type and select your new brushes holding the Shift key. Pressing the Save Set button you save the whole pack as an .abr file.
