Thinking of having your favorite photograph or computer generated image printed in large format with the intent of having it displayed for all to admire your creative work?
Here are a few simple guidelines to ensure that you get the best possible print quality.
First let's start with the actual image, for optimum quality this should be around 150-300dpi at 100%, the higher the better. So let say that you require an image that is 300dpi at A1 size (841w x 594h mm), if you were to open this file in Adobe Photoshop you would see that the file size would be 199.4MB and at 150 dpi it would be 49.9 MB, so as you can see the files required can be huge.
Many of today's high end digital cameras are quite capable of capturing images that can be printed up to and over A1 in size, especially the new 24 megapixel cameras currently available, this size & higher will eventually become a standard feature even in the smaller compact cameras which most people tend to use nowdays.
If you are using Adobe Photoshop you can assign a different color profile to your image such as the Adobe RGB or the sRGB color spaces, as you do this you will see the colors on screen shift slightly as they are mapped to the new color space. With the Adobe RGB profile colors will look more tailored, more vivid while the sRGB tends to look more natural, which profile you use is really a matter of personal choice and how you would like your finished print to appear.
Another important feature to ensure that your image will print just like it looks on your computer monitor is to use the "Proof Colors" option in Photoshop, when you use this option you will again see the colors shift slightly as they are mapped to the nearest printable color, to use this feature you would need an icc color profile of the output device (the printer), if your preferred print company are using a fully calibrated workflow then they will be able to email you an icc color profile which is a small file containing the print characteristics of their printers.
Printers are calibrated using a device called a spectrophotometer and some of the high end printers will have these devices built into them. The calibration process consists of first linearizing the printer by printing a density pattern, this pattern is then read by the spectrophotometer to ensure that the printer prints the correct density of ink from 0-100%. Once the printer is "linearized" a color profile needs to be created for a particular paper / ink combination. This is done by printing a color reference target which is once again read by the spectrophotometer, this information is then used by color profiling software to create a color icc profile of the printer and which can be used by Adobe Photoshop and other software to show how an image will print.
If a printing company is not using a color calibrated system and are just using the standard windows printer drivers (which many do) then this will lead to unpredictable color and the final print not matching the screen image, this workflow of course also relations on the computer monitors (both yours and heads) being calibrated in the first place, Google "how to calibrate my monitor" to see how this is done.
So you have gone to all the hard work of getting your image ready for print, the next option is to select the paper type, you should print onto a standard photo quality paper or onto one of the more expensive fine art papers.
While a standard photo gloss paper will produce lovely looking prints and are fine for general use you might want to take other factors into consideration such as how long do I want the print to last for and will it look as good in a few years as it does the day it was printed. If these are important factors then having your image printed onto a high quality fine art paper is highly recommended.
So what is the main difference between standard papers & high quality fine art paper, in one word "acid", it is the natural acid content in paper that over time causes it to yellow, curl, turn brittle & crack sometimes in less than one year.
Fine art papers such as Photo Rag by Hahnemuhle are made from 100% cotton fibers & are acid free, this means that they are archival quality papers and is the reason why galleries, museums and professional photographers use these papers for prints that will last. They also have the look and feel of an extremely high quality print.
While fine art papers can cost around three times the price of standard paper it's a price worth paying forpecially if the print is something you want to treasure for many years to come and you want it to look exactly the same as the day it was printed .