This tutorial will outline a way to scan large artworks and piece them together using a graphics program. The program used in this tutorial is Paint Shop Pro 8 but it can be adapted to other programs that support layers.

Step 1: Scanning
You'll have to scan large images in multiple pieces. Ensure the artwork is flush against the scanner edge, so the pieces match neatly.
Darker areas occur at the edges of the scan where the artwork isn't as close to the scanner bed, as it is in the middle. Give your scans plenty of overlap- a couple of inches- more for thick paper or board.

Step 2: Piecing scans together
Open a corner piece of your scans in a graphics program. Enlarge the canvas size to what you estimate to be the finished size of the work.
Open the adjacent scan to the corner piece, and paste it as a new layer on top of the first. Reduce it to ~50% opacity, and move it so it aligns with the scan underneath. Zoom to ensure a neat fit. Raise the opacity to 100% and use the eraser tool to eliminate the dark strip at the edge.
It's tempting to use a fuzzy eraser, which is ok for areas with little detail, but for detailed areas this makes the image blurry where the scans meet. Always use a sharp-edged eraser where possible.
After erasing the layers should look neat with no seams. Zooming out can help identify areas that need attention.

Step 3: Lather, rinse and repeat
When satisfied with the results, merge the layers and restart the process with the next scanned chunk of artwork. Or you could just take a digital photo of the whole thing to begin with....
If you don't merge the layers, that's up to you, although processing time will increase greatly with each successive layer.

All content copyright Donna Quinn.