I posted a while back on how Serif was using some custom fills in templates. I decided to try out creating my own after I got a feel for the image spec. Attached is a wpp file of the various fills I created (if anyone wants the original bitmaps, let me know and I will email you the zip file of images - about 5 mb).

In order to use the originals:

1) Unzip the fills
2) Copy the unzipped 'Custom' folder to the Serif > Webplus > Fills directory
3) Open Webplus and go to the bitmap fill button on the top tab
4) Righ-click on any fill and click Add
5) Browse to the new custom directory and pick the fill you want to import (I recommend embedding)

6) Create a quick shape
7) Color the shape however you wish by picking a color in the palette
8) Right-click on the shape and choose filter effects option
9) Check 3D Effects (reduce slider down to zero if you want a flat image)
10) Turn on preview
11) Check 2D Pattern Map and click the default Pattern checker icon
12) Browse to the custom folder and pick a any pattern
13) Adjust other settings as desired
13) Flip-flop and Scale are interesting

Enjoy,
Marcus

Serif forum link - Free custom bitmap fills