The world of paper sizes has standardized a lot on the A size ranges, well except for the USA which still clings to a multiplicity of inch based measures. So most of us now have A4 sized printers and scanners and life is easy, right?
Not quite, most photo systems are still geared to those American sizes, 4” by 6”, 10” by 8” etc. wasteful if you can only print on A4 sheets. It is ok most printers can not print to the edge of the page so a blank border is necessary. The conspiracy deepens because most pre-cut frames are also made to suit those inch based, so now perhaps a bit of trimming is required. The mistmatch becomes even more frustrating when it comes to flat bed scanners. Few of use want to scan nice A4 sheets, we want to scan thick text book, notebooks and even perhaps your own painting and sketched, like me. The trouble is whilst most of my sketch books are in fact A3 or A4 I like to paint on quarter watercolour paper sheets (which is approx 11" by 15"" and these are too large to fit on the scanner bed. The best watercolour papers are still largely "handmade" using same "Impreial sheets" (22" by 30") as in pre-industrial times. Interestingly the paper weight is now usually measure in grams, and 300 grams is my favourite.
The solution is really very simple, just scan the image in two (or more passes) and use your photo stitching software to paste the two images together.Voila! you have just doubled the size of your scanner. You need to ensure there is sufficient overlap between parts, 10% is probably the minimum 20-30% might be extravagant. If your stitching software is having trouble you can always add your own registration marks to the edge of the scan drawn on a price of masking tape if you don’t want to mark the work.
Most scanners will try to automatically adjust the scanning to get the “best” image quality and many now have “advanced” filtering but using photo software will also give you access to more control of colour bias, contrast and brightness controls, cropping and straightening than you Multi-function printer bundle includes. As I mainly manage all my picture in picasa I find the simple tuning and filters jus perfect to bring the scan as close as possible to the original.
An ordinary scanner & your favourite photo software can make a powerful combination