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Thread: Why not JPG?

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    Platinum Lounger
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    Why not JPG?

    I'm puzzled and seek a high-level explanation. Graphics and graphic processing is not my strong point.

    I have just placed an order for some T-shirts to be printed, front and back, with our logo. I attached a JPG file of the logo with the order.
    The T-shirt print shop says that a "Photoshop", "Illustrator" or "Corel Draw" would be better; that they can use the JPEG but their art work guy would have to convert it into one of the above forms, at a cost 9to us) of $30/hour.

    I'm puzzled because I thought that JPEG format was a reasonably standard type of object for communicating graphics. BMP I know works in almost any Windows application, but it is bulky.
    I would not have been unduly surprised if I'd been asked to resend in GIF, but it seems weird to me that a business that uses graphics as input to its processes can accept input only in a proprietary format.

    I have a copy of Corel draw somewhere, so I can install it and do the deed, but my puzzle remains - and if you can see it from my point of view, I'd appreciate some simple elucidation.
    Thanks

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    Plutonium Lounger Leif's Avatar
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    Re: Why not JPG?

    When you say 'print' - do you mean screen-print? If so, and it's multi-colour, they will need some software that can separate out the different colours for the separate screens. (Cyan, magenta, yellow and black, I think)

    Why not do them yourself? I can't imagine a young man-about-town like yourself doesn't have an iron, and we know you have a colour printer...
    Avery T-Shirt Transfers

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    Re: Why not JPG?

    Hi Chris

    I would put it down to the number of colours that the two options have in RGB (Red, Green, Blue) at 256 ^ 3 =16,777,216 colours, the GIF format uses 256 colours. This is fine for visual display units. However a printer uses CYMK (Cyan, Yellow, Magenta and blacK) viewing a standard printer it is only printing approximately 1,000,000 colous which are displayed completely differently as the primary colours of ink/paint and picked up differently to the human eye which is trichromatic (RGB)


    SSssssoooo if I have an image comprising true colour JPG (24 bit or 2 ^ 24 = 16,777,216.....hhmm a familiar number isn't it) and you convert it to GIF in a image processor the superfluous RGB coded colours are converted to the closest colour on the 256 GIF or 216 Gif web safe palette.

    They are using the generic language of the lumpen masses when they talk application level names but I would be slightly careful as these images have their own file extension and would suggest you go to the standard all encompassing GIF format.

    If you are willing to share you can PM me and I can do the conversion for you...for <img src=/S/free.gif border=0 alt=free width=30 height=15> <img src=/S/grin.gif border=0 alt=grin width=15 height=15>
    Jerry

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    Re: Why not JPG?

    If a printer tells you he needs your artwork in Illustrator or Corel format he likely has three things in mind. The most obvious is, as LEIF pointed out, is that he needs the CMYK separations to feed his printer. His second concern may be that he wants to have the right dots per inch (dpi) in your artwork to match the capability of his printer for best rendition. The last item relates to the size of the image you supplied relative to the size of the printing you want. If significant resizing is required then a vector format of your artwork is the desirable format to retain fidelity and Illustrator and Corel Draw can produce that. You provided him with a raster format file. Illustrator can convert raster to vector if needed for many pieces of artwork .

    Since your printer said the desired format could also be Photoshop, and that is a raster based program, then only the first two items mentioned above are relevant. If he does the conversion and all that is needed is to change RGB to CMYK, and if he charges you accurately then you probably are looking at $3 and most of that would be for creating a folder and naming it and all that overhead. The conversion is virtually instantaneous. But chances are they will also want to tune up the artwork given what they know about their printing process and what you requested. I would recommend letting them do it.

    The high level answer to your question is that your assumption about the universality of JPEG format is true only for the web (computers). In print media other formats are necessary. Also, if you include engineering drawings as "graphics" then JPEG, GIF, TIFF or PNG are not appropriate formats.

    Paul

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    Re: Why not JPG?

    > Why not do them yourself?
    Thanks, Leif. I saw the iron-on transfers in a store yesterday, but for this project I want to be SURE it works, and I feared that I knew so little about what is launderable etc that i should "buy" someone else's expertise.
    Screen print? Now you're getting all technical on me.
    I just figured that a printing-place would be able to accommodate any regular graphic.
    I hadn't figured out that they might have to do 3 or 4 passes (R, G, B and black, say).

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    Re: Why not JPG?

    > If you are willing to share you can PM me and I can do the conversion for you.
    Thanks, Jezza.
    I'll take you up on that offer on one condition - that you place an order through my new Toronto Dollar Print Shop (we accept only Toronto Dollars) and accept a whopping 90% discount on your first order. (grin!)

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    Re: Why not JPG?

    Paul, thanks for the most informative reply to my post.

    I now see the difference between, say, a laser printer spraying three sets of coloured powder onto paper in one pass versus a printer requiring three passes with a different colour ink at each pass. At least, I think that's how I see it. At least, laser printers and silk screen printers are different devices, so it is reasonable to accept different inputs for them.

    The sizing too makes sense. I have a feeling that "vector" specifies the start- and end-point, and hence can easily and accurately accommodate re-sizing, whereas raster is a hard-coded dots type of image, and extrapolation can introduce errors.

    I know little about programs, so your comment on Photoshop/raster, and the logic that implies makes sense to me too.

    And there I was, lost in my own little world thinking that JPEG was universal!

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