A Way to Scan your Artwork - Whatever its Size!

If you sell your artwork online, it's your responsibility to ensure you represent it correctly. We all want our work to look good on a webpage, but it also needs to look like the original - otherwise we run the risk of the customer being disappointed on delivery - none of us want that!
In theory, it should be easy. Get your work scanned, publish the result, and voilà!
In practice, anyone who's tried to do this knows that it doesn't actually work out so easily. I've tried numerous copying and print businesses, and the results have always been disappointing at best, and sometimes quite laughable at worst. This has driven me down the path of photography, and for the last couple of years I have sold both originals and prints on-line on the basis of photography. Photography is OK as a means of portraying your work, but it is very dependent on your lighting. I have tried photography under natural light, as well as artificial and daylight bulbs. The best I have achieved has been under a combination of all three. The problem, though, is that it's very difficult, without a very professional set-up, to ensure the lighting is the same for every photo. This involves a lot of work when it comes to making the prints look the same.
So what's the answer? I have long hankered after a reliable scanning solution, but there's a problem scanning large watercolours - they're too big for the scanner! As I've said, commercial copy solutions just don't seem to work. Perhaps their scanners are optimised for documents, and perhaps they just don't know how to work them properly. An idea crystallized in my mind, though, when I realised that my cheap scanner, embedded on top of my 3-in-one printer, got the colours closer than my SLR camera.
The problem was that whilst the colours came through well, the scanner is way too small to scan any of my works. All of my paintings are larger than A4 size, and that's the best my scanner will do.
It would be nice if I could even get a bit of my paintings onto the scanner glass, but I can't. Virtually all scanners are built with a 'lip', which is designed to help you position your A4 document, but which prevents you getting anything larger in contact with the scanner glass. And huge scanners are ridiculously expensive.
So I thought, what if I could get a standard A4 scanner which would lie glass-down on my painting and be able to scan accurately like that? There are loads of software solutions available to 'stitch' together different scans, so in theory if I could scan like this I could scan anything!

It's not a crazy idea - in fact it turned out that someone had already had the same idea. Here at http://hackaday.com/2013/09/27/hacking-a-flatbed-scanner-to-scan-very-large-documents/ I found a description of how to convert your cheap flatbed scanner to get glass in contact with the painting. This gave me the courage to do something about it - the original idea belongs to this article, but I'll describe more fully a few of the pitfalls you might encounter by doing the same thing - it's up to you which you'd like to follow.

So - here's the method I followed:

I bought a brand new Canon LiDE 200 scanner, took it out of the box, and took a saw to it! The reason I used this particular model is that the article I read said the LiDE series was all similar. Also, it's powered by only a USB lead, which is way more convenient than having to deal with a power lead too.

First, by bending the plastic lug that holds the lid in place, you can remove the scanner lid. It will go back on easily if you change your mind at this stage!

Next, I tore the lip from around the glass. It's attached in various places to both the scanner glass and the body. Remove the glass as soon as you can and put it somewhere safe. Where I couldn't tear the plastic away, I cut it. I think a Dremel-type small rotary saw would be ideal for this, but as I don't have one I used a craft knife throughout. I pulled off the plastic surround from around the buttons at the front of the scanner, and used a knife as a spokeshave to cut away the plastic around the rim of the scanner. This is quite beefy in places, and requires a fair amount of effort. Be careful! It would be easy to cut yourself doing this. A good way to ensure you don't is to place your hand inside the scanner body to hold it down on your workbench while you cut.

Your aim here is to cut away anything on the scanner that stands proud of the glass, without damaging the scanner mouldings that supports the bottom of the glass. It's not difficult, but is a bit of hard work if you're only using a craft knife! I kept refitting the glass to check where the plastic was still standing proud, and kept on cutting away.

This is quite violent work, and you might be worried about the scanner electrics being damaged. Well, yes. I found that the moving scanner bits kept coming apart, but it didn't turn out to be a problem. At one point I turned the scanner upside down, to check that the cables would work that way, and the CCD fell out, as well as a small spring! Although it's easy to work out how to replace the CCD (it fits in to a couple of lugs), I couldn't initially work out where the spring came from. In fact, it turns out that the spring is designed to keep the CCD against the glass, and fits over a little circular plug on the base of the CCD moulding - look for a Lego-like circular protrusion at the bottom left of the moving apparatus.

By keeping cutting away, you will eventually get to the stage that the glass is the highest part of the scanner all round. I found it easiest to repeatedly place the glass in its position with the scanner raised on a table, marking any areas of plastic that were still proud. Sooner or later, all the excess plastic is gone.

Cutting Down the excess plastic

At this point, your workbench will be a mess, and the inside of the scanner will be full of bits of plastic. Give it a bit of a vacuum, being careful to avoid sucking up the scanner's electrical ribbons. No matter how clean it looks afterwards, believe me that there will be chunks of plastic in the scanner's gears. So, carefully lift the moving parts of the scanner, and turn them upside down to expose the gears. I used a pair of tweezers to remove any swarf from the gears - there was lots, even after a vacuum! Replace the working parts by locating them in the lug and pushing down. The interior of the scanner is now clean, and the scanner working parts can traverse easily on their geared run.

Now clean the glass off with washing up liquid and a polish with a cloth. It needs to be clean. You'll have seen while you took the whole thing apart that the lip over the glass round the scanner detector's 'parked' position had a white sheet of plastic underneath it. This is for the white calibration of the scanner and you need to replicate it. Place a piece of white photo paper shiny side down, cut to the same dimensions as the original or slightly larger, over the glass and sellotape it down. Don't try to get away with using any other kind of paper - I did, and the scanner doesn't like it! Sellotape down all the other edges of the glass with about 1/4" overlap.

First Test Scan.

You're done! The scanner is now reassembled, and the working parts are trapped under the glass so you can use the scanner upside down. All you need to do is to place the hacked scanner face-down on your work and scan, ensuring you do enough scans to give a good overlap between them. Now you can use your favourite software to stitch the scans together. You can scan arbitrarily large works with an increasingly large number of scans, and stitch them together again.

I can't suggest any stitching software for Windows or Mac (although there's plenty), but the best software for Linux, which I use, is Hugin. If you use Hugin, you will find that the assistant doesn't work terribly well for scans ( just a feature of having what the software thinks is an unusual collection of lenses). However, if you follow this tutorial, http://hugin.sourceforge.net/tutorials/scans/en.shtml you'll find it works like a dream!

So now I'm chuffed to find that I can scan any size of image in sections, and stitch them together. I can enjoy the great resolution of a scan, together with a good colour reproduction, and then use software to decide what size (and resolution) of image I want to use. And all for the cost of a reasonably-priced A4 scanner! Sounds good to me.

Stretching Paper

Gosh, it's been a long time since I posted here - sorry. The problem is mainly that I've been working on a lot of commissions which haven't really lent themselves to step-by-steps. Now, before I know it, it's 4 months since I posted! OK, I'll try to do better now...

This painting has nothing at all to do with stretching paper! However, I thought I'd include it to decorate this post, because I like it, and because it shows how wet watercolour paper can get during a painting. It's called 'Dawn Breaking over Keith' by the way! It was painted by wetting the entire sheet, painting the sky fully wet-in-wet, and then, once dry, painting the land - again wet-in-wet. This painting used a lot of water!

Until you can handle wet-in-wet, you can't unlock the potential of watercolour, in my opinion. Some of the best effects you can create are done with the paper wet. And anyone who has ever tried to use lots of water on unstretched paper will know that the paper just warps and crinkles when it gets that wet. This means that the paint 'pools' in the furrows and runs off the high bits, making it impossible to get an even finish. It also feels horrible to work on. I think this is one of the main reasons why people try watercolour and almost immediately give up.

In fact, I recently did a step-by-step with an art group and I found that almost everyone had brought paper which was either unstretched, or had been partly stretched. The group members told me how difficult they had found it to stretch paper. Many had just taped down the edges of dry paper, which makes matters even worse: the paper wants to expand whan wet, but the tape prevents this, resulting in even worse 'cockling'.

So, in this post, I want to show you how I stretch paper in the hope that this may help you. I have found increasing difficulty in stretching paper over the years because, in my opinion, the quality of gummed tape available has declined. Sorry if you make gummed paper, but it's true! I've found that, increasingly, a stretched piece of paper would become ruined as it dried because the gummed tape had let go. I have a solution which has a 100% success rate for me, and I'd recommend it to anyone.

You need: your paper (this works on any paper of whatever thickness), a board which should be thick enough to resist bending, as the paper will pull hard as it gets stretched (I use 12 mm MDF board), gummed tape (the type you wet to activate the glue), some PVA woodworking glue (white glue) and a clean towel. Oh, and a bath, or something else you can fit your paper in to get it thoroughly soaked.

First, cut some tape into 4 lengths: 2 long and 2 short, to a few centimeters long than the sides of the paper. Put them to one side within easy reach.

Make sure the paper is the right way up. Many papers have a correct side for painting and a wrong side, although may are fine on both sides. The correct side is usually the one with the random, toothed pattern. The wrong side normally has a more regular pattern with less tooth. If the paper is watermarked, you should be able to read the watermark correctly, and not back to front. The best way to know which side is which is to follow the paper's sides from when you remove it from the pad or from the pack!

Keeping the paper the right way up, immerse it in the water and agitate it a bit to get rid of bubbles. You can soak the paper from a few minutes up to essentially no limit. Keep ducking the paper under to maximise its water take-up. There appears to be quite a discussion about how long the paper should be immersed for, with opinions varying from a few seconds to several minutes. What you are trying to do is get it wet, so I think a few seconds is way too short. I use Saunders Waterford and I soak from a few minutes for the 140lb paper up to about half an hour for the thicker papers.

Pull the paper out, keeping it the right way up, and let the water drain off as you hold it by an edge. Then, keeping it the right way up, lie it on an open towel, wrap the edges over and remove all the excess water. The paper is now damp and it will be continuing to expand, so don't hurry. Expansion is what you want. Keeping it the right way up, transfer it to your board.

Now, run a small amount of PVA glue around the edges of the paper and smear it into a film, staying within a centimetre of the paper's edge all the way round.

Now, wet a piece of tape (I start with the top edge, but feel free to be different!) by dragging it quickly across the water surface and letting it drip for a few seconds. Now stick the tape down, leaving at least a 1 cm overlap over the edge of the paper and smooth it down a bit. Repeat for the other 4 edges. Finally, wrap the edges of the towel over again and remove any excess moisture, being careful not to move the tape.

Now leave to dry naturally in a flat, horizontal position, preferably overnight. What will happen is that the damp paper will try to contract as it dries, but will be prevented from doing so by the tape. The tape will be assisted in holding against the strong pull of the paper by the glue, which dries as the paper dries, becoming stronger all the time. By morning, the whole lot will be dry, and the paper flat and taut, just waiting to be painted on! If needs be, you can use a hairdryer to speed the process but I think it's better to just plan ahead, and stretch paper before you need it.

Stretching paper like this will vastly increase your enjoyment of watercolour if you've not stretched paper before. If you've yet to take the plunge and try the medium, make sure you do this and start properly - it's worth the few minutes it takes.

There are other ways of stretching paper, of course: some people wet it and staple the edges down to the board. Others just use bulldopg clips to hold the edges. However, this is the method that I use. It looks great when dry, does not encumber your painting like I find bulldog clips can, and produces great results. Happy painting!