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		Have I selected the right colours in my scanning software? Is the scanning resolution appropriate? Can I make one scan different sizes? What should I know about duotones? What should I know about ppi, lpi, dpi and why should I care? Are my images the right size? When should I edit images? Should I compress my image files? How is a continuous tone image reproduced? What scan resolution do I need to set? Are my images sharp and clear enough? What should I know about blends?
	TO TOP	Have I selected the right colours in my scanning software?
		If you scan in RGB, make sure that you convert the image to CMYK before it is added to the page layout program and comes to Repros. NEVER TRUST YOUR MONITOR TO GIVE YOU A TRUE REPRESENTATION OF YOUR IMAGE COLOUR OR BLENDS. THE COLOUR GAMUT OF YOUR MONITOR IS DIFFERENT THAN WHAT CAN BE REPRODUCED IN PROCESS PRINTING.
	TO TOP	Is the scanning resolution appropriate?
		When scanning images, a higher pixels per square inch setting does not necessarily improve final output quality. For print jobs, the best result is obtained if you scan in twice as many ppi as there are lpi in the final output. That relationship will guarantee that you capture enough colour information to make an accurate halftone dot. Plan your page and image sizes before scanning to get the best images with the lowest file size and shortest output processing time. Do not increase the resolution of an image in Photoshop and expect it to output correctly at the increased resolution - the extra detail is created by interpolation (copying and duplicating the surrounding pixels) and the output image will be of poorer quality than the original image.
	TO TOP	Can I make one scan different sizes?
		In your page layout program you can scale up and down by 15% with little degradation of the final printed image. It is easier to reduce than to enlarge scanned images - pixels can always be thrown away when image size is reduced but pixels cannot be added back to maintain resolution if the image is enlarged again. If you wish to use a scanned image at a larger or smaller size, you must scan your original at a higher or lower ppi by multiplying your normal input (twice the lpi) by the percentage of the enlargement. For example an image to be printed 133 lpi and with a 150% enlargement would work like this: 133 x 1.5 = 399 ppi scanner resolution. To prevent aliaising (jagged edges), type and linework need higher input resolutions than continuous-tone photographic images.
	TO TOP	What should I know about duotones?
		Save duotones using the default values for screen ruling and screen angles. Colours should be defined as CMYK or spot, not RGB. Define colours consistently across image editing and page layout programs to avoid problems when outputing to film.
	TO TOP	What should I know about ppi, lpi, dpi and why should I care?
		ppi (pixels per inch) is a measure of the amount of information scanned in from an image. The finer the optics of a scanner, the higher the scan resolution and this is critical to image quality. lpi (lines per inch) is a measure of the frequency of the halftone screen used to print an image. A specific lpi is recommended for the paper stock being used. The lpi that you select in conjunction with your printer, affects the ppi used to scan in an image. dpi (dots per inch) is a measure of the output resolution of a printer, copier, imagesetter or monitor. For example: you may be scanning in a transparency at 300 ppi, because it will print on paper at 150 lpi and you are previewing the image on a monitor at 72 dpi.
	TO TOP	Are my images the right size?
		Be sure to crop and size your images during scanning or in an image editing program. If you crop them in your page layout program, the cropped portion remains part of the document and creates an unnecessarily large and harder to manage file. When you resize an image in your page layout program, this function must be calculated each time the file is printed. This can add significantly to processing time and may result in printing errrors. High res scans can safely be scaled up by 10% with no change in image quality. However after 20% perceptible degradation occurs. Scans can be scaled downwards with no restrictions and no degradation of the image but you cannot scale them back up again without loss of resolution. Down scaling discards pixels and if you decide to scale your scan up in size, the image is degraded by interpolation. If uncertain of how you are going to use an image, use a copy of the scan file until you are certain of the final output size and then scale your original scan down.
	TO TOP	When should I edit images?
		Always edit your images (resize, crop, rotate, flip, composite) in your image editing program, not in your page layout program. Rotating or flipping your images during scanning saves your page layout program from the time-consuming and memory-intensive calculation of the rotation, flip etc every time you print.
	TO TOP	Should I compress my image files?
		It is best to compress all your files with Stuffit as a single self extracting archive. Files that are compressed with Disk Doubler are okay but learn to use Stuffit. Stuffit enables you to compress several files into a single compressed file which can be self expanding with no change to the folder and file relationships. Self extracting archive files are essential for sending work to Repros via email.
	TO TOP	How is a continuous tone image reproduced?
		Photographs, transparencies, multi toned graphics are all continuous tone images and to be printed they must be converted to halftones of various sized dots that create the illusion of a continuous tone image. The quality of the copy that you input will determine the quality of the the reproduction that you output.
	TO TOP	What scan resolution do I need to set?
		Continuous tone images usually require 300 dpi whereas pictorials, graphics and type require at least 600 dpi for density and sharp focus.
	TO TOP	Are my images sharp and clear enough?
		All scanned images look a little soft and fuzzy compared to their originals. Some scanners have automatic sharpening routines built in. Also most scanning and image-editing programs provide sharpening filters that are menu-selected. Photoshop has Sharpen, Sharpen More and Unsharp Masking (despite its name) functions which apply increasing amounts of sharpening. The dynamic range (ability of the scanner to capture detail in both the highlight and shadow areas of an image) affects the quality of the scanned image more than resolution. The higher the dynamic range, the more a scanner can record the differences between two closely matched colours with drum scanners providing a superior quality scan. It is common to apply a Sharpness tool or use Unsharp masking in an image editing program to images captured by a digital camera. TOO MUCH SHARPENING CAN BE VISUALLY OBJECTIONABLE. OVERSHARPENING IS NOT ALWAYS DETECTABLE WHEN VIEWING AN IMAGE ON A MONITOR. BE SURE TO TEST THE VARIOUS SHARPENING LEVELS OF YOUR SOFTWARE AND TO PROOF THE RESULTS. Sharpening carried out by Repros as a matter of course on the scanner is generally more satisfactory than subsequent applied sharpening in desktop programs and is usually all you need for a normal image.
	TO TOP	What should I know about blends?
		Vignettes or halftone gradients should print as a continuous blend, from light to dark. If you can see bands of colour, you've got banding! Banding can occur when too few steps have been used in creating the blend, when a low-quality output device has been used, or from a postscript error. Photoshop outputs the best blends to film while Illustrator blends are satisfactory but never as smooth as Photoshop. QuarkXpress and Pagemaker blends are poor and have a strong tendency to band. If your graphics program has a blend feature, use it automatically to calculate the number of steps required. Applying a noise filter can also yield good results. In general, the greater the change in tonal value and the smaller the length of the blend, the better the output result. Try to stay away from fade to zero blends. The higher the lpi, the more noticeable the banding.
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