prbimages

A few people have asked me about my method for reformatting images for greeting cards (see my previous journal entry), so here is an explanation of what I do. This is not the only approach, nor is it probably the best, but it seems to work OK for me.

You need to be willing to do a bit of arithmetic (a calculator is useful!), and you need some image-editing software for resizing your image, and for adding borders (I use Photoshop).

BACKGROUND INFORMATION

In this old forum thread Justin French explains the basic details of card sizing. The main points we need to know are:

1. Cards are C6 size, 114 mm by 162 mm (4.49 inches by 6.38 inches).
2. Cards are printed at 200 dots-per-inch resolution.
3. One inch is equal to 25.4 mm.
4. A little bit, 1-2 mm, gets trimmed from three sides of the image when printed. The fourth side which is the “spine” of the card does not get trimmed.

DESIGN PROCESS

First, you need to decide how you want to “frame” your image on the card. This will vary depending on the shape and content of your original image, and what kind of effect you are looking for. As an example, for this photo I decided on a centered framing with a thin white line around the photo and then a thicker black border extending to the edge of the card:

For this photo, the image is centered horizontally but is higher than center vertically, and it has a black outline then a wide white border:

The borders can, of course, be any colour you like, they can be thick or thin or patterned or whatever, the only thing to remember is that a small amount will get trimmed when printing, so don’t put anything important too close to the edges of your final design.

THE DETAILS

My aim is to produce an image that is exactly the right size for a card when printed at 200 dots-per-inch (DPI). I find it easiest to work in pixels, so let’s restate the card size in pixels:

1. 114 mm is 4.49 inches which is 898 pixels (at 200 pixels-per-inch).
2. 162 mm is 6.38 inches which is 1276 pixels (at 200 pixels-per-inch).

So we want our image to be arranged appropriately within a “box” sized 898 by 1276 pixels. If we take Justin French’s post at face value, we would then add an extra 1-2 mm (13-25 pixels) around three edges, with the expectation that this extra portion will be trimmed during printing. However, I have found that doing so does not quite work as expected – it tends to produce an image which is just slightly off-center. Instead, I have found that it works better to arrange the image within a box sized 910 pixels by 1276 pixels, and then to add 12 pixels to the short dimension and 24 pixels to each side in the long dimension. The final image will end up being 922 pixels by 1324 pixels.

This sounds complicated in words, so here is a diagram:

In the diagram above, I have resized the image to an appropriate small size, added a thin border, then added white space to each side and to top and bottom so that the overall size is 910 pixels by 1276 pixels. Then finally I have added another 24 pixels of white space to the top and bottom, and 12 pixels to the right hand side. (I’m saying “white space” but it could well be “black space” or any other colour, of course.)

I have found that a good size for a thin border is three pixels, and a good offset from the edge of the card is 100 pixels (which is half an inch, or 12.7 mm). Of course, you can use different numbers if you like in order to achieve a different end result.

AN EXAMPLE

To make this a bit clearer (I hope) here’s what I did with Tulip Glow:

This starts off as a square image, and I want it centered horizontally on the card. I decide on a three-pixel thin black border, and I want it offset from the edges of the card by 100 pixels on the left and right, so thats 2×3 + 2×100 = 206 total pixels of border. The target card width is 910 pixels, so my image must be resized to 910 – 206 = 704 pixels wide. Using Photoshop, I go to Image -> Image Size and set 704 pixels as the width, making sure that “Constrain Proportions” is ticked. I click “OK”.

My core image is now the right size, 704 pixels square. Next, I add a three-pixel black border by going to Image -> Canvas Size, tick the “Relative” box, and enter “6 pixels” into the Width and Height boxes. Make sure the “Anchor” is set to the center so that the six extra pixels are added equally on all sides, giving a three-pixel border. Set the “Canvas extension color” to Black and click “OK”. The thin border is done, and our image is now 710 pixels square.

OK, next we want to extend the canvas out to the edges of the card, using White this time. Again, go to Image -> Canvas Size and enter 200 into the Width box. This will add 100 pixels of white on both the left and right sides. Set the “Canvas extension color” to White and click “OK”. The total width of the image is now 910 pixels, as desired.

Now we want to add more white to the top and bottom, but this time we want more white at the bottom than at the top, to give a pleasing balanced design to the card. Our image is currently 710 pixels in height, but our target height is 1276 pixels. So we have to add 1276 – 710 = 566 pixels. We might choose to add, say, 200 pixels to the top and 366 pixels to the bottom. We do this by using Image -> Canvas Size twice more. First, put 200 pixels in the Height box, and set the “Anchor” to the bottom square to force the newly added pixels to appear on top of the image. Then repeat, putting 366 pixels in the Height box and setting the “Anchor” to the top square, forcing the new pixels to appear at the bottom of the image.

We now have our nicely formatted card image … sized at 910 pixels by 1276 pixels. To finish off, we need to add a little bit more to the top, bottom, and right sides, which will mostly be trimmed off during printing. So, using Image -> Canvas Size twice more, add 24 white pixels to the top and bottom, and 12 pixels to the right, and it’s all done!

Get the card printed, and everything should be nicely centered and professional-looking.

DISCLAIMER

There is one thing that Justin mentions in his forum post that I linked to at the beginning of this Journal, and that is that RedBubble could, at any time, decide to change the way the cards are printed. If they do that, then of course it is possible that the way the cards are sized and trimmed will be different, and these instructions may no longer work well.

Anyway, I hope this is understandable and helps in some way,

Yours, prbimages.