How many ppi for 300dpi

Discussion in 'Digital Darkroom' started by anesh, Nov 7, 2005.

  1. A pro label printing company requested that I design my labels to meet their output of 300dpi. My question is how many ppi should my document be?
  2. Does it depend on how big a print they want?
  3. Generally for printing, the PPI specification is for the actual output size. Discuss this with the printer.
  4. This means sending a 300 pixel per inch image; for the Label size you want. Thus a 3x4" Label would be 900x1200 pixels; ie 3x300 by 4x300. The reason they ask for this is quality. Some folks might submit just an image at say 100 ppi; and then get mad "because the printer company screwed up". This is REAL common with the lay public; as regular as the sun coming up each day. This also means a real 300 ppi image; not an upsized one from 30 ppi to 300ppi; that really appears poor with text and fine detail. The "300ppi" number depends on the actual printer's printer. With some of my printers; a 400 ppi image will appear somewhat better; especially if a "microfont from hell" is used by the customer. A good lable can be made with lower than 300 ppi; it just depends on the FONT sizes; Font style; Logo details; image details. Some fonts work well at really low resolutions.
  5. If you give them a 1200 x 2400 pixel image at 600 pixels per inch; tell them what you REALLY want. This type of input is common too; the order gets "put on hold"; until the intent is ironed out and documented. This is a 2x4" image at 600 ppi in Photoshop; or it could be changed to 4x8 " @300 ppi. Irrate customers will say in is obvious. Photoshop certified customers tend to be the worst; and real cocky; ie like experts who dont know what the size of a 2x4 is. Most order forms define them label size; but then there is a border sometimes; ie the forbidden zone that one cannot print on. One can print to the very edge effectively by printing a larger sheet; then trimming; this adds alot of cost.
  6. Ppi and dpi are unrelated terms. Pixels per inch defines the resolution of a monitor or camera sensor. Dots per inch is the output from the print heads. In either case, the more dots or pixels per inch, the higher the resolution. But there is no direct relationship between the two. I think you need more specific info from your printer as the terms are often used interchangeably, which they aren't, and incorrectly.
  7. Is the PPI / DPI distinction useful in any way? I ask not to be flippant, but because I'm hoping to learn something.
  8. They describe the resolution of two distinct media, one electronic pixels, the other drops of liquid ink on paper. To use the terms interchangeably would be like using amperage and horsepower interchangeably. They both describe power, but one is electrical, the other mechanical (now admittedly the hybrid engine muddies my analogy a bit)
  9. yes here we are talking about two supports : the inks(paper support) and the pixels, this means for the paper support its lines per inch and everybody says a 300 dpi output but the definition is: for a magazine that print in 133 lines per inch the pixel image can be from 1,5 or 2 times the lines per inch, this means that a 240 pixels image will be printed with the same quality as a 300 pixel image.
  10. dpi goes back many many decades; in fascimile; ie FAX. It was used in scanner specs for fax; before there was a microporcessor. Later 1970's books used dpi and pixels; sometimes the same way; because each dot WAS one Pixel on the print hammer's on early printers. There was no confusion before "Photoshop experts" arrived. Scannera have used dpi in their specs; in patent literature; before digital cameras existed; or photoshop.

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