Scaling graphics for a box truck wrap

[bob]

To be clear, design at 72-100ppi and print at 720x720dpi in standard mode. Only rip lossless formats like TIFFs and PDFs. If you guys are ripping JPGs, you're shooting yourself in the foot.

Nonsense.

A jpg created with no compression and no smoothing has only trivial loss, if any at all. What you don't want to do is keep loading, diddling, and resaving jpg's. If you create a jpg as the final result from other sources and you actually understand your equipment the results are indistinguishable from tif's or any other bitmap format.

A pdf is merely a container not a file format. More often than not, any bitmaps imbedded in a pdf are jpg's.

 

[Fred Weiss]

To be clear, design at 72-100ppi and print at 720x720dpi in standard mode. Only rip lossless formats like TIFFs and PDFs. If you guys are ripping JPGs, you're shooting yourself in the foot.

If that were true then please explain why virtually every stock photo site from the best to the worst distributes in JPG format.

 

[ProWraps™]

jpg argument aside, a bit of info i left out is that we pretty much stick with tif format. but we also have used jpegs from clients. they work fine if there is no compression. as mentioned above, jpegs dont ruin quality. compression does. this can be said with any format that uses a quality setting if the quality setting is reduced.

 

[grafixemporium]

Nonsense.

A jpg created with no compression and no smoothing has only trivial loss,

Funny. You call it nonsense, then admit that there is indeed some loss with JPG files.

When utilized properly, TIFFs are a lossless file format with no data compression whatsoever. This means the file sizes are quite large. All JPGs are compressed files... regardless of how "trivial" the loss is, there is loss. There is no such thing as an uncompressed JPG. Of course, the amount of compression (or loss) is adjustable, but no matter what when PSD, AI or CDR file is saved as a JPG, pixel information is averaged based on the JPG compression algorithm, thus, lost.

Fred, stock photography sites use high quality JPGs because of size limitiations. If file size was not a factor, photographs could remain in a raw format or converted to a lossless format such as a TIFF. The problem is, Fred, when you download a stock JPG, you are already dealing with a compressed image. When you use it in your PSD layout and then save it as a JPG, you are further compressing an already compressed image.

On a side note, you're right about PDFs Bob... but like PDFs, TIFFs are just containers too. The TIFF format has the ability to hold compressed JPG data, vector data, layers, etc. Anyone who knows even the basics of preproduction knows how to configure PDF settings to ensure their files are top quality with no compression. TIFFs can also be used as a lossless file format for flattened images... and that is primarily what we print.

So, given the choice, why would you save your PSDs as a JPG and print from less than perfect files when you can just as easily and quickly save as a TIFF? Why on Earth would you save your vector files as JPGS and lose those beautiful crisp lines that vectors produce when you can save as a TIFF and maintain that pure clarity?

 

[Blizare]

Thanks grafixemporium. You saved me some time this morning by typing that

 

[javila]

So, given the choice, why would you save your PSDs as a JPG and print from less than perfect files when you can just as easily and quickly save as a TIFF? Why on Earth would you save your vector files as JPGS and lose those beautiful crisp lines that vectors produce when you can save as a TIFF and maintain that pure clarity?

The space savings on an 11 compression jpeg vs an lzw compressed tiff is enough for me. Any artifacting that shows at that level of compression would be hidden away by the dot printing nature anyways.

Artifacting from jpeg compression doesn't show it's face unless you're compressing them at 75% or less.

That vector ->bitmap comparison is really weak btw. The difference between a low compressed jpg and a tiff is nowhere are large are you make it out to be.

Javila I do not understand this statement because I have laid out things at 72 PPI and printed at 720 x 720 DPI as well as laid things out at 150 PPI and printed at 720 x 720 DPI.....There is a noticeable difference in quality so one (in my eyes) obviously has something to do with the other when creating a file to print.

The higher ppi is giving you a better print, nothing more.

The combination of image resolution and printer resolution determines the possible color gamut per image pixel. Merely divide the printer resolution by the image resolution, square it, and then take the number of colors your printer is ruining plus 1 to that power.

Dividing the printer resolution by the image resolution and then squaring that number yields the number of printer pixels per image pixel. Taking the number of inks plus 1 [for the color of the media] to that power yields the number of possible colors per image pixel.

Tradition wisdom says that you should try for at least a 4:1 printer to image resolution ratio. Anything much less than this will severely limit the possible color gamut per image pixel.

I keep reading this, and it makes no sense.

Your color gamut comes from 1)bit depth of the original file 2) printer profile creation 3)Color space translation

Image resolution has nothing to do with achieving a high or lower gamut.

 

[javila]

delete me.

 

[Wildpony]

For Me, storage space is not an issue and I always save as tiff (LZW) and not jpg. Only time I save as jpg is if I'm emailing someone a low rez copy.
If I start with an image that is a jpg, the first time I modify it, I save it as a tiff. I also like to keep the layers separate for later editing, can't do this with a jpg.

 

[javila]

I keep the original files as their native formats. The jpgs are only done to send to the rip.

 

[bob]

...

Image resolution has nothing to do with achieving a high or lower gamut.

Really? Assume that you're printing at exactly the same resolution as the image, This gives you exactly one, count it, one, printer pixel per image pixel. That printer pixel can only be one of the, say, 4 colors of which the print is capable or the color of the media. The possible colors per image pixel is 5.

Now print at exactly twice the resolution of the image. This gives 4 printer pixels per image pixel [2 in the x direction and 2 in the y direction]. Each of these 4 printer pixels can be one of the, say, 4 colors of the print or the color of the media. Thus the possible color combinations per image pixel is 5^4 or 625. Not a whole hell of a lot of colors.

Printing at 3 times the image resolution gives 9 printer pixels per image pixel. This allows for 5^9 or 1,953,125 possible colors. A lot but still far less than the full standard 32 bit CMYK palette.

Now print at 4 times the image resolution. This gives 16 printer pixels per image pixel. This yields 5^16 or 152,587,890,625 possible colors per image pixel. This figure is larger the full CMYK palette thus all colors than can be printed will be printed.

Comprende?

 

[javila]

That's the wost logic regarding color space I've every read, I don't know where you picked up that "knowledge" but don't go back to it, and stop spreading it around.

You can print the same color gamut with a 2ppi image that you can with a 300 pi image if you keep the same color space,bit depth, printer profile, and media.

What you can't do is designate more color values to a certain physical region, but that has nothing to do with actual color gamut.

 

[DO Grafx]

I basically work in around a third scale. I build at 300 dpi so that the image can be blown up three times it's size without using clarity. It's a little faster to build that way for me on my machine. And keep in mind... you DO lose print quaility if not at 100%.
If you pull a.jpeg off the web at 72 dpi and change it to 100 dpi, the picture gets bigger and of a lesser quality.

 

[iSign]

I know I don't know a whole lot about this complex crap... but I know enough to notice that a bunch of people know less than they think they know.

 

[kalvix]

riping a large vector image with gradients, clipping masks and the what not can take upto 10 hours and we have a quad core. the loss we experience with converting to a 100dpi jpeg (which will rip in less than 10 minutes) and printing is negligible for large format, and well within the acceptable visual range.

 

[petesign]

Hate to resurrect this old thread... but I have a few questions.

If the highest resolution my printer will print at is 720x1440 - what dpi do i need to design in to achieve this resolution before I rip the file (to reduce pixelation)

For instance, I have this customer - comes in and asks me to print a jpg he gives me at 20" x 20" -- (slaps forehead) -- then when I open it and show him how pixelated it will be - I offer to create something similar for him to use instead. He says "okay" -- today I contact him, and he tells me the shop who will be completing this job (huh!?) wants it in 600x600 DPI resolution.

Now, silly me, I instantly think 600dpi? Why on earth would someone print an image at 600DPI? Then I think - my printer prints 720x1440.

So which is it?is a printer's resolution not measured in the same way we could consider pixels per inch?

Thought I was pretty up to speed about DPI, but someone asks for 600x600...

Oh, I also told him that if someone else was going to print it, he should also design it.

 

[Malkin]

DPI is frequently confused with PPI, sometimes even within some software.

DPI is your printed resolution, the number of ink droplets per inch. This number is usually higher. I don't think you can provide a file with a certain DPI, it just isn't possible.

PPI is the number is pixels per inch in your raster image (jpg, tiff...). This one people are more likely to be familiar with.

Generally there is no need to bother with anything over 150 PPI for sign work.

 

[petesign]

I have rarely used anything higher other than business cards. It wasn't the DPI or PPI question, as though they are different, most folks seem to swap the two terms without really meaning a difference. My question is more about - if I send a 150ppi file to my ripping software and it rips it to 1440x720 -- it's not really a 1440x720 image.. it is printed as such, but in truth, it is a 150x150 image, correct?

Who in the WORLD would ask for a 600ppi file to print on? How would I convince someone coming thorough my doors that if I designed a 20" circle logo to be printed on translucent material at 150ppi, that it would indeed be good enough.

after all, 600x600 dpi is 600ppi is it not?

I understand 300dpi for high quality prints on paper, 72dpi for web graphics --- and that designing in 150 for my signs is pretty good... but when someone goes out and says they need a 600x600 resolution per inch, i think what? On my mimaki, I understand that 1440 is the resolution (dots per inch) it can print in one direction, and 720 in the other.... but what does that actually equal? -- does that question make more sense? Then you have the question, what kind of material are you printing on? I can print at the same resolution on one material and it doesnt have any dithering at all... then you go to something else, and the ink doesnt saturate the same way - so it looks like someone painted with a sponge on it (okay, maybe not that bad) - but you get the idea.