Printing
Printing documents, posters and booklets might not be that obvious as it seems. Here you can find some pointers how to prepare your file before printing.
Contents
Resolution
A common mistake is to use images with low resolutions. On the other hand images with too high resolutions increases your file size.
For regular printing a resolution of 180 DPI (dots per inch) will suffice. Higher resolutions are unnecessary because your eyes will not be able to distinguish the dots on your print. You can even use lower resolutions if your image or poster is viewed from a greater distance.
If you want to use images for (professional) offset printing you need a minimum resolution of 300 DPI. Offset printing is used for high volume printed matter, like newspapers, books, magazines etc.
| Print resolution | Image size in pixels | Image size in cm | Image size in inch |
|---|---|---|---|
| 180 DPI | 300 x 360 px | 4,2 x 5,1 cm | 1,7 x 2,0 in |
| 180 DPI | 180 x 216 px | 2,5 x 3,0 cm | 1,0 x 1,2 in |
| 300 DPI | 300 x 360 px | 2,5 x 3,0 cm | 1,0 x 1,2 in |
If you want to render a full size poster, then you will have to determine the size of your poster in pixels. (See table below)
| Paper size | 120 DPI | 180 DPI | 300 DPI |
|---|---|---|---|
| A4 | 992 x 1403 px | 1489 x 2104 px | 2481 x 3507 px |
| A3 | 1403 x 1985 px | 2104 x 2977 px | 3507 x 4962 px |
| A1 | 2807 x 3973 px | 4210 x 5960 px | 7017 x 9933 px |
Color
A document can use different color modes. Most common is RGB or CMYK. For regular print jobs use RGB even if your printer uses print cartridges with cyan, magenta, yellow and black.
Offset printing uses only CMYK.
Change the color mode of your document always to RGB before printing.
Borders
Every printer has a minimum print margin, also called a non-printable area. Beyond that point a printer cannot print. If you print a full-size image on paper you will always see a white strip around. If you don't want a white border you need to cut it off course.
Bleed and crop marks
Bleed is the printed area at the border which will be cut off after printing. To know where to cut off you need crop marks printed.
With some programs like Indesign you can print crop marks to see where to cut the paper. Not every program can create crop marks. If you create your own crop marks, make sure they are located inside the printable area. With other programs which can't create crop marks you have to make it yourself.
