Digital concept art: Size and resolution?

[TsunamiZ]

For drawing and painting professional digital concept art in Photoshop, what are the dimensions and DPI generally used? For example: 8x11 in. 300 DPI. I particularily want to know what DPI is commonly used for digital painting. 300 DPI, 200 DPI, or what? Thanks.

***When I said DPI, I meant PPI. Sorry didn't know there was a difference.***

[bizarre]

dpi is irrelevent.

pixel dimensions are what you're looking for. just find what you're comfortable with.

[Blue]

i try to work larger then 2000x2000 on all my drawings. Lets me add the needed detail without counting pixels and I can always print it poster size after.

Thats just me though.

[Rascar Capac]

dpi is irrelevent.

it is? I always go 300 and no less...

[Qitsune]

It is, unless you want to print it out afterwards.

[Rascar Capac]

well yeah - nobody prints out their portfolio anymore? At least ONE hard copy?

[Pillick]

I have kind of a related question -

I wanted to print out one of my drawings today so I called up a printer place. I wanted to find out how big I could get this image printed based on its dimensions in pixels. The people there just answered with "We dont work in pixels, we work in millimeters" - not very helpful, given this thing is entirely digital >.<

So as a rough guide, how do pixel dimensions relate to physical print size? How much can images be stretched before they start looking like ass?

[Chingwa]

don't hurt dpi's feelings! dpi matters a lot!

[_Mario]

Well DPI is not that irrelevant. If you have a picture that is 5 x 5 inch at 300 DPI then that picture woule be 5 x 300 = 1500 x1500 pixel.
If you need to print something then you need to know your DPI because that will relateto the quality.
If you have a picture that is 2400 x 2100 pixel in size then you can get (at 300 DPI) an 8 x 7 inch picture. If you make it bigger then there won´t be enough information for the bigger area.

It depends on what the printer can manage and whatquality you need.
Is it for a book (text) that should not pain your eyes, is it a poster (you don´t need that much detail because you will look at it from some distance).

I think that´s how it works.

Pillick: Aske them what size they can print, and what DPI they have (and what they reccomend for poster size[or whatever you need]) and then open a new file in Photoshop with the size (in mm/cm whatever they said) and DPI.
Then open your picture and paste in into that blank canvas.
You will see if it´s too big/small/whatever and can adjust it

[Ilaekae]

Man...I must really be tired. I accuse some of you guys of giving bonehead info out, then I post something even worse. I've just corrected the following to include something I left out that made a mess of everything...a conversion factor between PPI and DPI...sorry about that. The following is now correct...

For clarity, I also changed what most of us refer to as DPI on a computer to what it should be--PPI (pixels per inch). When I use the term DPI (dots per inch), I'm referring to PRINTING, as in commercial printing, not a laser writer or laserjet...

************************************************** *****************

I really hate to disagree with my betters/elders, but...

...you guys really have to get your act together...because SOME of you don't seem to know what you're talking about...

PPI/DPI IS NOT IRRELEVENT! PPI/DPI MATTERS! IT MATTERS A HELL OF A LOT IF YOU WANT TO BE A PROFESSIONAL!

[For the sake of this discussion, "ppi" is being used in the computer sense of pixel measurement--300 ppi IS 300 pixels per inch, but most people, and a lot of apps, use dpi and ppi interchangeably. Most people get fucked up and confused when they start talking to a commercial printer, because "dpi" to them is only DOTS per inch of the final reproduction. For example, newspapers repro at maybe 65-85 dpi, high-speed junk magazines at 100 to 200 dpi, and high quality repro like posters, art prints, and other hi-grade printing usually goes at 300 dpi or (rarely) more.

This has nothing to do with your artwork. It has to do with the quality of the printed image.

In order for your art to be successfully RIPed to printers' negatives, though, it has to meet certain minimums, and this is where you have to deal with the computer artists' version of "dpi" (PPI).

(1)
True line art: this would include typography, black and white "hard-edged" art, and line work like inked technical drawings and pen drawings done freehand.

Best reproduction is to save as a Tiff at 900-1200 ppi for SAME-SIZE reproduction. In a pinch, I've gone down to 600 ppi for some loose hand art at same-size, but don't recommend it. Obviously, if you plan on reducing the reproduced image, you can use a proportionately lower dpi for the original.

(2)
Monochrome and full-color art is usually designed to rip at 300 ppi, either as Grayscale or CMYK, at SAME-SIZE.

The exception is if there is typography or line art included in the art, say as callouts or dimension lines and arrows, the ppi should be upped to between 500 to 900.

NEVER USE RGB COLOR FOR REPRODUCTION ART! IT MUST BE SPECIFIED AS CMYK. PERIOD!

ALL OF THE ABOVE ASSUMES YOU ARE PREPARING ART FOR COMMERCIAL PRINTING (posters, illustrations, etc.)

If you are preparing art for online or monitor display, like a website or powerpoint shit, and such...and have no intention of ever having it commercially printed...

Your art will be displayed at 90 "dpi" (this should actually be "ppi"--pixels per inch--and it's 72 on a Mac), no matter how much extra shit you try to pump into it. An image that's 900 x 900 pixels will be displayed at 10" by 10" on most standard monitors.

This art should be prepared or converted to RGB and is best as a JPEG. If you're not too concerned about quality, you can use a GIF.

IMPORTANT: There is NO direct one-to-one comparison between PPI and DPI. You can't assume that if you are going to commercially PRINT at 300 DPI, that 300 PPI is okay. There is a conversion factor (1.55) necessary to prevent pixelation from occuring. What you do is find out what DPI your printer will be using on your printed piece (150, 200, 250, etc.) and multiply that number by 1.55. This will give you a number that is the MINIMUM pixel size in PPI (pixels per inch) you should work for same-size reproduction.

To explain this so it makes sense, I'll use TsunamiZ's specs as an example...


To answer TsunamiZ's question specifically...

If you want to print an image as a 300 dpi 8.5x11 full-bleed, you should have art that is approximately 465 PPI (which would be approximately 4000 x 5200 pixels. If your reproduction doesn't have to be at 300 dpi (and it almost never does--this is an extremely high dpi for most commercial printing)--say it's 150 dpi--your art can be done at roughly 235 PPI for perfect reproduction/conversion (2000 x 2600 pixels). If you were going to reproduce your art at 17" x 22" with a 150 DPI screen, and your art was actually 8.5 x 11, you would have to use a PPI of 465 (twice what you need for a SAME-SIZE reproduction) because your art is being blown 2X.

Does that make sense to anyone out there? It sounds complicated as hell, but it's not. You have to recognize that pixels are not dots. In order to go from DOTS to PIXELS, you must multiply by 1.55. (You also must actually multiply by the scale percentage if you're not using SAME-SIZE reproduction)

This is probably easiest if stated as a formula...

PPI = DPI x 1.55 x %

PPI is the pixels per inch you must work in.
DPI is the dots per inch your work will be reproduced at.
1.55 is the conversion factor.
% is the amount of reduction or enlargement that your will undergo. Obviously, if you're working same-size, this figure will be 1 (100%).

[Rusty]

dpi is irrelevent.

how dare you! *smack bum

A4 at 150dpi an up, A3 300 dpi and A2 600 dpi..There are a few exceptions depending on file type but this is a good guideline.

..Jace

[TsunamiZ]

Ilaekae:

***When I said DPI, I meant PPI. Sorry didn't know there was a difference.***

[Ilaekae]

That's alright, TsunamiZ...it gave me a great chance to post like a pompous ass...

[figure2]

There is a conversion factor (1.55) necessary to prevent pixelation from occuring. What you do is find out what DPI your printer will be using on your printed piece (150, 200, 250, etc.) and multiply that number by 1.55. This will give you a number that is the MINIMUM pixel size in PPI (pixels per inch) you should work for same-size reproduction.

This is the 1st time I have seen that particular formula. The convention I was taught was that you multiply the dpi (or lpi: lines-per-inch) by a factor of 2. If I remember correctly I may have even gotten this formula out of one of my earlier Photoshop user manuals.

For example, the standard printed linescreen for a trade magazine is between 133 - 150 lpi. If you double the higher number you get the target image resolution of 300 ppi. As far as I know, this is why most people use 300 ppi images if they will be professionally printed.

A word about lpi: the dot patterns that most professionally printed images are made of are acttually in rows or lines. Just in case anyone was confused.

[Ilaekae]

Figure2, the 2x factor is a safe rule of thumb that's easy to remember, especially in the modern comp environment. The figure 1.55 x % comes from my graphic arts background, and we've used it as a guideline for years because (especially in the "early" days of computer pre-press) we had to find the absolute minimum that could be used for the production of usable negatives. We didn't have the nice toys around today, like xxgigabyte drives and Zip disks, so everything was pushed to the limit to insure that we ended up with the smallest files possible. Many of the older presses that normally run standard screens in the 150 lpi range still automatically request 240 ppi files out of force of habit.

The biggest problem with just stating 300 ppi for "everything and you'll be safe" is still that many younger people who grew up with comps only and never went through the pre-comp press prep process often forget (or don't understand) that if art has to be enlarged more than a small percentage, 300 ppi is definitely not enough.