Never use JPEG in your workflow
JPEG’s save space, allow faster loading, processing and ripping, they also give good colour reproduction, so why should you never use JPEG’s in a print workflow?
JPEG’s are possibly one of the biggest pains in reprographics. Next to LZW Tiff files they cock up more ‘quality’ jobs than any other file format and believe us over last 30 years of digital reprographics we have seen hundreds. Many of today’s brochures and magazine use JPEG’s quite successfully. They have numerous advantages over other file types, which is why they are so common. But in the wrong hands they will ruin any job.
Compared to a PSD or Tiff file, JPEG’s are lower quality. You can more or less always tell that a particular image was saved as a JPEG because in areas with strong contrast you can see compression artefacts. The stronger the compression the more JPEG noise or artefacts. Most other file formats use lossless compression. These files are larger than JPEG because they use a fully recoverable (lossless) compression that preserves all of the original image data. These file formats offer full quality at all times, no matter how many times they are saved.
This is why you never use a jpeg
JPEG compression algorithm changes image data while converting it. Amount of change can be controlled, but not its location which is always noticeable around sharp colour changes and across gradient areas.
JPEG FILES WORK BY THROWING AWAY DATA. THIS DATA CANNOT BE REPLACED – EVER.
If you use JPEG’s in your workflow then somebody, at some point in the future is going to use this file incorrectly. They are going to increase its size to save time, they save again reducing further the quality. While many JPEG’s, even poor quality ones print ok, do you really want to loose a customer because of an error than can be avoided simply by using a better quality workflow?
JPEG general information
- JPEG is primarily an RGB format.
- It is also fine for print but beware it’s pitfalls.
- If you save a JPEG image several times, you’d end up with an unusable image. Because every time you save you throw away even more data. Photographers always make the mistake of saving their JPEG file again, thus giving the end user an inferior file to their own original.
- JPEG’s cannot be restored to its original.
- You can remove some compression artefacts in Photoshop.
- In print always save JPEG at the highest possible quality and set to baseline standard.
- For web save at Quality 8 or 10 progressive. Remember this image should be optimised when in your chosen app.
When to use JPEG
If you are processing 100’s of files every day, JPEG’s being a smaller file offers a credible and faster solution. It is deciding when you can use a JPEG and when not.
Newspapers are typically printed in a resolution of 85 lpi, while some magazines may print at 133lpi or 150lpi. At these lines per inch even poor quality images print reasonably well. If you are producing in a hi end magazines or brochures for printing at 200lpi or stochastic printing, quality is everything and poor image will be noticed especially against a quality image.