I created the above group of planks using the techniques I am going to outline here; hopefully even with the jpeg compression you'll agree that they aren't bad.
Let's start by building one plank. For this example I'll start with a 512x512 image because of file upload limitations but when you make your own wood you may want to keep my tip in mind and make it bigger.
1. Create a new image 512 x 512 with a black background.
2. Select EFFECTS: NOISE: ADD and set it to 50% Random Noise.
3. Select EFFECTS: BLUR: MOTION BLUR and set the angle for the direction of the grain and the blur to 40 pixels.
[Note: In PSP7 the maximum motion blur was 40 pixels. When I tried the PSP8 demo I note that the new motion blur leaves some 'stretched' lines the last 10 pixels or so of the blur. If you have this problem create your images a little bigger -say 16 pixels on each side so that after you create the image you can crop off the edges.]
4. Convert the image to grayscale COLORS: GREY SCALE to wash out the colors and then convert it back to full color (unless you like rainbow wood) COLORS: INCREASE COLOR DEPTH: 24 bit; then resize it to Height: 64, Width: 512.
5. Select COLORS: HISTOGRAM FUNCTIONS: EQUALIZE and you have your basic wood pattern. Later in this tutorial I'll show you some ways to improve the grain further and add more character.
A quick tip right at the out set....if you are going to go through all effort of creating some detailed wood planks make them a bit bigger than you need to increase reusability. For example if I want to make a crate 512 pixels wide I actually prefer to make the planks 1024; then I can use them to make other wooden items and by repositioning them and changing the color layer I make it less likely that people will say "Hey this bozo used the same plank on the door, floor and chest!"