Dealing with giant graphics

LivingPharaoh

New Member
Hello folks,
I'll condense the background on this as much as possible: running in an election. Party decided I'm only worth a couple thousand flyers, and no posters. I go to get a couple printed myself without knowing DPI or DMYK from Adam, but I asked my party's graphic designer to make me a poster of the dimensions of 420 x 594 millimetres (A2) and like a pro, he did. Then I learned what DPI was and that the print company asked for 300 resolution. Oh, and a 3mm bleed on the sides. So my problem is this:
I work with GIMP (GNU Image Manipulation Program) and attempted to resize the DPI/pixels to meet their needs - this turned out to be 49606 x 70157px which makes my reasonably-fast computer seize up and takes ages - crashing altogether three times. Even if I did finish this mammoth task, the file is likely to be a few gigabytes in size as a project file 10th of the size stood at 1GB.

Does this company know what they're doing or am I missing out on something? Would it be worth my very modest campaign funds to commission one of you folks to ewsize and convert it to DMYK?

Thanks
 

Levi

Moderator
Staff member
Ignoring any sort of scaling issues (ie low quality images don't upscale well) how on earth did you calculate 49606x70157px for 300dpi a2...actually I think I know what you did now I think about it mm are divided by 25mm for inches, not 2.5 :p.
My quick calculations make a 300dpi a2 as 5040x7128px although another site says it's 4961x7016 pixels (I assume they're being a bit more accurate than my 25mm equals an inch lol).....+ whatever it would be for the 3mm on each side... this should not make your pc freeze.

Really really rusty with gimp but your page size should be set for 426x600mm with a dpi of 300.... I make that 5112x7200px pixels so shouldn't be that much different. Now that 3mm on each size is basically 'cutting space' for the printers so make sure any edge colours expanding into them while making sure nothing important is stuck near them too.

You're also talking about CMYK not DMYK, which at it's most basic is the way it's going to be printed, CMYK basically means cyan, magenta, yellow and key (aka black).
 

LivingPharaoh

New Member
My quick calculations make a 300dpi a2 as 5040x7128px although another site says it's 4961x7016 pixels (I assume they're being a bit more accurate than my 25mm equals an inch lol).....+ whatever it would be for the 3mm on each side... this should not make your pc freeze.
I used this calculator form on NinjaUnits.com which gave me 420 mm @ 300DPI = 49606px. Is it reasonable to expect such a company to scale the dimensions of my source file as needed?

Re: scaling. When I experimented with converting my low resolution social media "poster" to DMYK it seemed to mask pixelation. Think it might have something to do with colours bleeding into each other more seamlessly.

I appreciate this help. Most stressful week in years so far :LOL:
 

Levi

Moderator
Staff member
I used this calculator form on NinjaUnits.com which gave me 420 mm @ 300DPI = 49606px. Is it reasonable to expect such a company to scale the dimensions of my source file as needed?

Re: scaling. When I experimented with converting my low resolution social media "poster" to DMYK it seemed to mask pixelation. Think it might have something to do with colours bleeding into each other more seamlessly.

I appreciate this help. Most stressful week in years so far :LOL:
That site is just wrong.... I have no idea what it's calculating but it's not the horizontal and vertical pixel dimensions that's for sure lol. It does seem to be about 10x the actual number so I wouldn't be surprised if they've screwed up and used the calculation for cm's instead of mm's.
As to pixelation, honestly without seeing it it's a bit hard to comment.
 

hankscorpio

Moderator
Staff member
300 DPI for a poster is overkill.

They are viewed from a distance so you don't need 300 dpi anywhere from 100-150 dpi would be fine.

I used to have a calculation for it but here it goes found on another website.

Viewing Distance---Min Resolution
0.6m / 2ft ------------300 dpi
1m / 3.3ft------------180 dpi
1.5m / 5ft------------120 dpi
2m / 6.5ft -------------90 dpi
 

hankscorpio

Moderator
Staff member
You don't need to do anything here - there's no need to convert to CMYK either.
Find another company to work with for the printing of your posters.

Terrible service, and no clue what they're doing.
 

LivingPharaoh

New Member
You don't need to do anything here - there's no need to convert to CMYK either.
Find another company to work with for the printing of your posters.

Terrible service, and no clue what they're doing.
Thank you for the advice. I suspected as much on the first go around, but then they rejected my work again. I very politely informed them I no longer need their services.
 
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