using gimp to prepare figures for science journals at 600 dpi

acari · **Joined:** Jul 16, 2019 **Posts:** 5

Hi Gimpers,

I am trying to use gimp to make 600dpi figures of line drawings for and article in a science journal. So I scanned the ink line drawings at 600 dpi usually as a pdf output or a tif. Then I import into gimp and type my text on the image telling the reader what's where and what's what and including the scale in mircometres.

Then I export as ... a tiff and I am ready to load up to the journal's web portal ... but when I do, I see that the file is only at 300 dpi ... that's too low for the journal... must be 600 dpi. Very long face... :-(

What am I missing here? I have had a look on the web for clues but here I am still looking. Thanks,

Yours etc
John M Clark
Acarologist (Mites)

Wallace · **Posted:** Wed Jul 17, 2019 12:08 am **(#2)**

acari wrote:

Hi Gimpers,

I am trying to use gimp to make 600dpi figures of line drawings for and article in a science journal. So I scanned the ink line drawings at 600 dpi usually as a pdf output or a tif. Then I import into gimp and type my text on the image telling the reader what's where and what's what and including the scale in mircometres.

Then I export as ... a tiff and I am ready to load up to the journal's web portal ... but when I do, I see that the file is only at 300 dpi ... that's too low for the journal... must be 600 dpi. Very long face... :-(

What am I missing here? I have had a look on the web for clues but here I am still looking. Thanks,

Yours etc
John M Clark
Acarologist (Mites)

Hello John and welcome to Gimp Chat.

* * *

After opening the image in Gimp.
I would go to Image > Scale Image and check that the dpi/resolution is what's required.

acari · **Joined:** Jul 16, 2019 **Posts:** 5

Thanks for that;
Image > scale image. set to 600 in options.

Pretty sure I tried that. Check. Yes. I did. so I am missing something still.
John

Wallace · **Posted:** Wed Jul 17, 2019 12:44 am **(#4)**

acari wrote:

Thanks for that;
Image > scale image. set to 600 in options.

Pretty sure I tried that. Check. Yes. I did. so I am missing something still.
John

Do you have a way of checking the image file's properties,
before you upload it to the journal?
This might be something,
which is happening during the upload of the file.

acari · **Joined:** Jul 16, 2019 **Posts:** 5

Thanks again,
I think that could be worth a look. For what it's worth the four images are about 370 - 870 KB as line drawings on A3 paper. Does that sound like 600 dpi? also wondering if I needed to do the >greyscale then > scale image before I typed all my symbols on image? I like puzzles .... this one's tricky.
John

Wallace · **Posted:** Wed Jul 17, 2019 1:39 am **(#6)**

acari wrote:

Thanks again,
I think that could be worth a look. For what it's worth the four images are about 370 - 870 KB as line drawings on A3 paper. Does that sound like 600 dpi? also wondering if I needed to do the >greyscale then > scale image before I typed all my symbols on image? I like puzzles .... this one's tricky.
John

That seems a bit small for 600 dpi.
Scale to 600 dpi before adding symbols.
If the images are going to be in color, greyscale will not work.
However if the images are B&W, it shouldn't matter if they're greyscale or not,
but I would check with the journal.

Blighty II · **Joined:** Sep 23, 2016 **Posts:** 317

acari wrote:

For what it's worth the four images are about 370 - 870 KB as line drawings on A3 paper. Does that sound like 600 dpi?

Bitmap images have sizes in pixels, not dpi.

An A3 page has a size of 420x297mm. At 600dpi that translates into a size of 9921x7016 pixels. Is your image that size? Gimp shows the image size in pixels in the title bar - top left corner.

Next question: what will be the print size of the image (in inches or mm). For 600dpi the required image size in pixels can be determined.

acari · **Joined:** Jul 16, 2019 **Posts:** 5

yes. That's the size of file. It's also what the online file checking site gives me when I use it. Print size will be less than A4. I will explore the last question you ask too.
Thanks for your help.
John M Clark
Acarologist (Mites)

acari · **Joined:** Jul 16, 2019 **Posts:** 5

Thanks Blighty,

It is indeed to do with print size. I think I can see why my file size of figs is still showing as too small. File size c. 58 x 82.5 cm at 600 dpi required in journal portal but I have drawn on paper half that size, A3, in area which is c. 30 x 41.5 cm. so my files have 300 dpi showing. I will try to solve this in the morning.

This is a really good site!
Yours etc.
john

rich2005 · **Joined:** Mar 04, 2011 **Posts:** 2612

Quote:

I export as ... a tiff and I am ready to load up to the journal's web portal ... but when I do, I see that the file is only at 300 dpi ... that's too low for the journal... must be 600 dpi

For your completed, finished, ready to send to publisher image. Post a screenshot of the dialogue Image -> Print Size and that will tell all.

Some things to remember:

Quote:

I scanned the ink line drawings at 600 dpi usually as a PDF output or a tif.

When importing a PDF into Gimp it is up to you to set the ppi. The Gimp default is only 100 ppi.

Quote:

Print size will be less than A4

You scan A3 but the printed version is less than A4 There is going to be some scaling either by you or the publisher. You can change the Print Size in Gimp from A3 to A4 just by adjusting the ppi. Does not scale your image in any way but ppi is 1200 which might not suit your publisher.

If you need to scale it to a specific size and ppi for printing, not difficult but you need to follow a sequence. see: https://www.gimp-forum.net/Thread-Chang ... 8#pid14278

Finally: If you begin with a 300 ppi canvas (Gimp default A page sizes are 300 ppi) and copy/paste or Open-As-a-New-Layer a 600 ppi image, the result is 300 ppi. Need 600 ppi ? then start off with that.