HOW TO SCAN LARGE ARTWORK

Using an A4 Scanner and Photoshop

By David Denton

If you are an artist, it can be expensive to get someone else to scan your artwork. This guide will show you how to scan and edit it yourself using an A4 scanner and Photoshop.

The first step is to scan the painting. Starting in one corner of the painting, take the first scan. It is very important to make sure that the edge of the painting lines up exactly with the inner lip of the scanner; this makes it easier to merge the scans together later.

After this take subsequent scans, moving the painting a little each time and ensure that there is plenty of overlap with the previous scan (I tend to overlap by a third each time). Make as many scans as you need to cover the entirety of your painting. Normally I take 10 or 12 scans for a painting measuring 30cm x 70cm.

In Photoshop, create a new document (File - New) about 10cm larger than the size of your original painting, this is where you are going to assemble your final image.

Open your scans in Photoshop. Go to your first scan and click Select - All (or cmd A on an Mac, Ctrl A on a PC) and copy it using Edit - Copy (cmd C on a Mac, Ctrl C on a PC).

Go to your new document and go to Edit - Paste (cmd V on a Mac, Ctrl V on a PC). Click on the move tool and move the scan into roughly the right position (if you can't see this toolbar, click on Window - Tools).

Repeat this process with the next scan. There are two things that you will notice: it is hard to get the position of the two scans to match up exactly and you will be able to see the edge of the scan too. This is all due to the scanning process. Let's look at how we can sort it out.

Firstly let's deal with the position. You will see that you have now got three layers: the blank background and your two scans. (If you can't see the layers click Window - Layers.) Make sure that Layer 2 is selected and then reduce the opacity to 50%.

Reduce to 50%

You can now see through the top layer to help you line them up. Zoom in (View - Zoom - Zoom In) and use the move tool to get the scan in roughly the right place, then make fine adjustments using the cursor keys. You won't get all of it perfectly in line but concentrate on getting the important areas of the painting right.

Increase the opacity of the layer to 100%. Select a large soft-edged eraser (about 200 px is about right for my image but you may need a different size).

After checking that you are still on Layer 2, erase areas of the overlapping layer to reveal the first scan. You may need to undo if you make a mistake and erase too much. Keep going until you've got it how you want it to look.

Erase here

Then repeat the process with the remaining scans.

There may be some tricky areas that you just can't get right when you do the erasing stage. In that case, scan just the tricky area again and repeat the process again. On my painting I had to do this with the head.

And the finished image looks like this.

For more information on my art visit:

www.daviddentonart.com