Cropping photos for printing

by Artbloc on 26/02/2010

If you want to offer a service of printing people’s photos onto canvas, you’ll need a quick way of preparing your images for printing. Time is money and sizing/cropping images can take an age if not thought through properly.

You are sent a photo that you need to print on your canvas roll. Your customer wants it printed using 38mm Gallery Stretcher bars, at say, 60×45cm. Where do you start?

It will be the wrong shape usually so how’s best to crop it? What will happen to the edges that need to be wrapped? You need to crop it to size, but you don’t want to lose part of the image if it can be used as part of the wrapped edge.

The simple answer is a pre-sized template. You can make these up in advance. One for each size you offer. Now when you get a photo to print, all you need to do is drag it onto the template and straight away you can get an idea of how it’s going to work out.

Your templates should already be set at your printing resolution. (see our other article about that). Also you should add guidelines that indicate where the front of the canvas will be and how much you need to allow for the wrap. 38mm gallery stretcher bars would need 4.6cm whereas 18mm standard stretcher bars need only 2.6cm of image for the sides. Also allow some blank space top and bottom. 3.7cm each end will do. This is important if you are printing multiple photos on your canvas roll. Without this blank space the photos will be too close together and won’t leave enough canvas for you to grip when stretching.

When you drag your photo onto the template you’ll see how much you need to enlarge the image to fit. You can decide at this point if you need to contact your customer and request a better quality image.

Cropping your photo. Example 1

In this first example, the image has just been dropped onto the template. You can see that it’s quite small compared to the size you need to print, but it’s acceptable. Now enlarge the image a bit…

Cropping a Photo, Example 2

You can easily see now that the photo is the wrong shape and will require some cropping to make it fit. But now you’re not guessing,  you can see how you’ll need to crop it and see what part of the image will do for the sides. You might even decide at this point that you’re going to have to print it with white sides.

Just slide the photo around resize it, while all the time you’re seeing how it will look when printed.

There are several methods for fixing awkward photos which will be covered later.

What DPI should I print my canvas?

by Artbloc on 25/02/2010

So,  you have bought your new large format printer, you’ve stocked up with your gallery stretcher bars and inkjet canvas rolls. Now what? Set your printer to best quality 1440dpi and off you go!

Not quite. You don’t need anything even close to 1440dpi!

My printer can print at 1440dpi so why would I use anything else? It comes down to time and money. Printing at 1440dpi can use more ink than a lower resolution. Time is a big factor too. 1440dpi printing takes far longer to print.

When you are printing on either a natural media like cotton inkjet canvas, fine art canvas or a synthetic media like polyester inkjet canvas the texture of the canvas is very forgiving.

None of the following is relevant when printing on photo paper rolls, but if you are printing on inkjet canvas, read on …

When printing on a cotton canvas or a polyester canvas, you don’t need to print at anything more than 180dpi. Yes 180dpi. Set the printer itself to 720dpi either in the driver or in your rip software. The files you create though don’t need to be anything more than 180dpi.

We’ve tested many canvases and have proved to ourselves, that printing at resolutions higher than 180dpi do not improve the quality of your print when printing on an inkjet canvas. 180dpi prints onto a canvas look perfect. You can’t improve on perfection so stick to 180dpi.

The texture of your canvas roll is really the determining factor.  Below about 180dpi you will start to see fuzziness in your image. Once you hit around 180dpi you stop seeing any improvements in image quality.

This has many benefits. Your library of images you print from takes up far less space.  When printing, your images process much faster.

180dpi was also chosen because it’s an exact multiple of the printer’s native 1440dpi resolution. Keeping to multiples means that the interpolation of your image is more accurate. It probably doesn’t make a noticeable difference when printing on fine art canvas or polyester inkjet canvas, but I think it’s a good practice to stick to. You might start to see a difference when printing images with thin lines or tiny text on premium inkjet photo paper.

Colour profiling. What is it, do I need it and how does it work?

February 25, 2010

What is colour profiling: Basically colour profiling makes sure your print, whether it’s on cotton canvas,  polyester canvas or photo paper roll, always comes out looking the same as the image on your screen. When you scan a photograph for instance, you’ll expect the image on the screen to have the same colours as the [...]

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How big a stretched canvas can I print?

February 24, 2010

People new to canvas printing may buy a used 24″ wide printer and think they can produce a stretched canvas 24″ wide.
The truth is you are looking at a stretched canvas about 6 inches narrower than the width of the printer or canvas roll/sheet you are using.
An example. If you are printing on a 24”(610mm) [...]

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How to stretch a canvas

January 28, 2010

Folding the corners on a stretched canvas is where first timers get into a mess. Watch here as we show you a quick and simple way to get neat and tidy corners every time.

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