Vehicle wrap DPI & vinyl.. opinions please?

[Brian Hays]

I would say at a quick guess not having thought about it much 50-75 dpi would be fine.

If you were to take a photo or image that was the size of a van and 300 dpi the file size would be HUGE! In fact BIGGER than HUGE! Also you certainly wouldn’t be able to originate the artwork yourself I would guess.

Then again I am no expert 🙄

[Allan Weyman]

Rob,

I generally try to stick to between 65 and 100dpi. Towards a 100 is a bit more preferable. I find if I am scanning an A4 as a rule of thumb if you scan at around 400 to 500dpi you end up with a A1 at a good print resolution of around 75dpi.

It is not just the file size of the image, when it rips (I use a Colorbus hardware rip) it makes a monster file about 6 times original. I just let the rip get on with it and do something else but it can take 20 minutes or so chewing the fat before it starts.

Mind you if you want to see some large file sizes I have a Colortrac 800dpi colour scanner, scans 1 mt wide any length, so if you ever are given a poster or a newspaper or something as an orginal look us up I will do a good deal for board members.

Incidently up to now I have been using the aforemention FIRST vinyl system which does not need lamination.

Allan

[Brian Hays]

Allan, how big is an 800dpi full colour file at 1m square. Is it HUGE or is it HUGE?

Just out of interest I just looked at the render to bitmap function in Signlab, it rekons 2048mb! Obviously this can be compressed but it’s still gonna pretty big.

[Mark Candlin]

Rob,

As with most things its a matter of compromise. When dealing with large graphic images file sizes can become very large and unworkable. Try it yourself in photoshop and see what a difference dpi makes.

A one metre square print at 150 dpi will generate a file 858 meg.
the same size at 100 dpi is 380 meg.

Dont forget you’ve got to work these files in photoshop, generating text adding effects, layers etc. Large file sizes will take an age to work on and save especialy if using a lot of layers even on a top spec computer.

Also be aware that ripped files for output are a lot larger than the source image, a 1gig image can become 3 times that size when ready for print.

There is no point going over 100 dpi for large images it simply isnt worth the agro for the small gain in apperance.
People dont get on their hands and knees and look from 3″ when they see a wrapped vehicle and think “mmmm image looks a little soft from here” They see it from 10ft away and think “WOW look at that!! ”

It also depends on what sort of image you intend to use. A photograph for example means you can drop the dpi right down to between 50-75 dpi and still look ok. If you are using a lot of text go for 100 dpi or consider adding the text in normal flat colour vinyl ontop of your wrap vinyl.

As for vinyl choice I would go with the reccomended choice your printers gave you. I use grafiwrap and laminate with good results, a lot of people use it, Avery do a good cast wrap as well.

Hope this helps.

[Allan Weyman]

Yes I would agree with Mark on that one, Photos can be a lot less. I actually did a full size cut out for some boy’s Barmitzfa (you can tell I am not of the faith I can’t spell it!) and as his mother gave me a real C-rap photo (by a professional I may add) I had to use my Olympus digital camera in the end which will produce a 1 meg file. When I took it up to life size it was about 25 dpi, I resampled it up to 75 which will only smooth the jaggies a bit but worth while. When printed it did not look half bad and the customer was well pleased.

Text as Mark says is more of a problem and I noticed on Grapityp’s van the actual text was overlaid cut out vinyl which may be a better way of going. At least that way a message or telephone number change is easy.

Brian: As for an 800dpi 1mt x 1mt scan as a native tiff file which the Colortrac works in it probably would not go on a CD, (750mb +). What I would do in this case is get it into Corel PhotoPaint and save it as a .jpeg which will shrink it way down to as much as 10% of the original. Jpeg as you probably know is a good format for transporting files as long as you
don’t keep opening and saving as it will loosen up.

I have this Colortrac scanner sitting here cost me a fortune and is a bit under used but it is a great machine and as I said if any member wants to use it post me the originals and I will save the scan onto a CD and post back for a reasonable price.

Allan

[jon vital]

Mark explained everything very well.

We’ve used the Grafiwrap too and it was good.

If you want to start doing big digital stuff make sure you get a good spec PC with at least a gig of ram so you aren’t constanty using the swap file.

[Robert Lambie]

Thank you very much for the info guys. More than appreciated!

I understand about what is being said about file size etc.
I will not be creating the artwork nor will I be printing it..
Are we saying that the artwork should be created at 75dpi at actual size?
Then printed at 75dpi?
If this is the case then im easy, that’s what will happen. I just never imagined it to be printed so low a rez.. ahh you live and learn eh?

Back to the wrap.
I’ve listened to what you have said. Thank you!
My beliefs on wrapping a laminate are “be wary” but wrapping using a cast?
I am aware of Avery now promoting their cast as a wrap equivalent. Obviously that’s what the grafi-wrap is about too. And judging by your comments doing a good job at that.
For my own piece of mind I think I will have to go with mactac on this one.
Not because I think anyone is wrong, simply because I haven’t used grafiwrap and don’t want to experiment at the exspence of my customer.. Ultimately my own if anything goes wrong.
Always go on a gut feeling as they say!

[Allan Weyman]

Robert,]

That is exactly right, 75dpi at actual finish size is spot on and I came to that conclusion through trial and error so it is nice to see others agree with my findings and reached the same conclusions. Bear in mind what was said about the text though.

Allan

[John Childs]

Robert,

The printer we use (same one I wonder?) also recommends Graphityp. I too wasn’t particularly happy with this but went along with it.

Although we haven’t done any wraps with it we have been over some fairly serious curves and I have to say that we haven’t had any problems yet.

Regardless of this, you must go with what you will be comfortable with. You have to sleep at night.

[Neil Kelly]

We spec all our digital prints at 50 dpi actual sise we dont print inhouse but all the prints we have had at that spec have been OK we try not to incorporate text and add that as a vinyl graphic after the print is fitted
Ive posted a pic of a job I did last week in showus your stuff. The vinyl was Avery (easy apply)
It went on a treat and ill think you will agree the quality is more than good enough.

Neil…

[Rodney Gold]

Hiya
you cannot really talk DPI as a printed graphic cos even a 1440 dpi machine will actually map pixels to “cells” of dots to get colours etc.
The printer prints “cells” per inch commonly called LPI (Lines per inch)
a CMYK device prints only 7 colours and a laser prints only 1!! So what happens is these colours get distributed in cells to fool the eye that the combination of these either gives another colour or a shade of grey.
Generally the device cannot map one pixel to one dot it lays down so thats why a 600 dpi device does not need one pixel per dot , it actually cannot use it.
a 1440 dpi device *might* be able to print 300 lpi , that depends on the cell size.

There is a simple rule of thumb , the file must be from 50-150 pixels per inch of printed output – do not confuse this with dpi – as dpi only applys to the output device.
IE for a screen whichi is a 72 dpi device , a 1″x1″ graphic scanned at 720 dpi will result in a 10″ x 10″ display on that screen and if printed on a 360 dpi device will result in a 2″ x 2″ print.
Size is really all that counts when doing digital printing – you also really have to know what the LPI figure for the printer is.

Lets take the case of that 800dpi pinrt that was talked about and lets use a value of 75 pixels per inch. There are 40″ in a meter , thus the print would be 3000 x 3000 (40×75) x3(RGB colour “depth”) which translates to a 27 meg file. even if you use 150 pixels per inch , the file size is 108 mb.

Generally , one would leave the graphic in its native colour space , IE scanned or digital photo type stuff should be left in RGB. Don’t convert for the person that is going to print as they normally set up colour transforms specific to the media and inkset and machine in their RIP.
Most RIPS can handle both vector and raster graphics so text is actually NOT a problem unless you have converted the WHOLE file to a bitmap – it and other vector graphics should print crisply despite what the rasters size is withing that graphic.
EPS or PDF is the best way to send a file , both maintain vector and raster graphics (tho can be pretty big) – Converting the whole file to a JPEG is the worst.
As to the mactac issue , you have to use a mactac inkjet specific conformable vinyl for digital prints – mactac will tell you that some of their conformable vinyls are not suited for printing , we learnt the hard way!!!
Best results we have had are on starrex or the graphityp stuff.
If a customer want to use a specific material that will rint ok , we use it for them.

As to lamination , well if you had to order a print without lamination for a wrap , I wouldnt guarantee it for a day no matter HOW it was printed.
Most lamination film supply co’s produce a conformable laminate (cold pressure) suitable for wraps. There are some hot melt laminations that are petrol , acid , solvent etc proof and are VERY good and not expensive. However for mechanical abraision which is the bugbear of wraps , you must use a proper film.
The films also have other effects – like a soft matt will smooth grainy graphics and hide scratches from washing etc , and a gloss lam will “punch” insipid graphics a bit. If you have issues with delamination or conformed graphics shrinking , either the lamination or the method of applying it to the graphic was wrong. another point about lamination is that it tends to allow slit cutting when wrapping the vehicle without the cut growing or edges curling and lifting.

In terms of processing large files and ripping them , the processor speed is by far the most important issue , then comes the graphic cards performance , then RAM and then HD – a ripped file can be gigs big , and even if you have a ton of ram , the files still page to HD.
Most printers , having spend vast amounts of money on the Printer would shell out for a really fast box to RIP or manipulate on , even so it can take time to mess with files.

[Allan Weyman]

Rodney

When I and the other guy was talking about text we were assumming a 100% bit map file to be fair, and you are quite correct if printed from Illustrator, CorelDraw etc. a combintation of bit map and vectors prints absolutely fine. Incidently I find CorelDraws’ print engine absolutely superb for doing this type of work, in fact anytype of print work.

Your points about lines per inch are spot on as well, so many people who come into my shop with huge files on cd to print out an A5 leaflet cannot get their heads around the fact that the scan does not need to be at the same dpi as the printer can print at. I do work for a local college and they teach this sort of stuff and they still can’t get their heads around it.

I would take up one issue with you and I will try it today when I get to work, the size of a scanned image 1 square mt at 800dpi, in tiff format will produce a file far bigger than 108meg. If I converted that to a .jpeg as I said I could probably shrink it down to 10% of it’s original size.

I will post the resulting file size tonight when I get home as I don’t surf during work time as I’ll never get anything done!

Must get off now.

Allan

[Rodney Gold]

Hiya , sorry , I assumed the image was to be *printed* by a 800 dpi device , i’m not sure why one would want to scan at 800 dpi for this size?

A 1m x 1m image scanned at 800 dpi would be humoungous , 40 x 800 x 40 x 800 x 3 for RGB and 40 x 800 x 40 x 800 x 4 for cmyk – RGB would be 3 gig file and CMY would be a 4 gig file- erk:)
The problems with JPEGs are that they lose colour info at every save.
There are “lossless” compression algorithms , but there seems to be no universal adoption of one type (Png? perhaps)

We deal with print brokers , ad beureas etc – amazing how *dof* some of them can be in regard to resolution and or colour.
Whats worse is that with NO extra overhead , I can print the graphic to the best of my printers ability , no extra time , no extra inks etc and what I get is as pixelated as all hell and can never have the “pop” that a better print will give.

I hate folk that have done their own colour transforms and embedded ICC profiles , its very difficult to fix. We ask for colour proofs when colour is an issue and have printed various pantone swatches to match exactly or at least show what the output will be.
Mostly we get ppl moaning that the colour they saw on their screen is not what we printed , or the ubiquitous “here’s my business card , please do me a 3m x 1m banner with my logo”
I have just one problem with Corel (Ver 11) it is VERY slow regardless of the puter its used on and despite my having set stuff to supposedly make it faster , it’s definitely a lot slower than say version 9.
the biggest problem is that me and my ppl are far more conversant in Corel and resist going to PS7 or AI10 or FH10.
I like Corels import/export filters too as well as its price and our lasers , cnc machines etc all run off it.

[Allan Weyman]

Hi,

Well I scanned in an A0 (= 1 square metre) and it produced a huge 2.76 gigabyte tiff file, so there you go, virtually unworkable.

I find .jpeg a good file type for transporting files about as long as you don’t keep editing and resaving. If it is burnt to a CD as read only I fid them perfect fine to work with.

No the 800 x 800dpi x 1 mt square was merely a question asked by a Brian Hayes as what size file it would make on my Colortrac scanner. He estimated 2.48gig so he was close!

Allan

[richard clark]

hi guys,

following from everyone’s answers, here are mine.

Scan an image at 300 dpi at around A3 size. Print this using your output device, and then downsize the image in photoshop or similar using dpi of 200 dpi, 150 dpi, 100 dpi, 75, 50 & 25 dpi. Using just about any desktop inkjet you will see that there is no difference in image quality from 150 dpi and above. Using the remaining prints yu can decide youself what resolution is adequate for the job in hand.

Regarding wrap materials, we specify Grafityp cast wrapping vinyl with laminate for permenant wrapping applications. We never have an issue with this product WHEN professionally fitted. For shorter term applications then VWS is recommended. Easy to apply without application tape etc.

regards

Richard

[Allan Weyman]

Blimey Richard how long do you think we get on the job, that would take a while doing that and how many out there have the luxury of an A3 scanner, not many I’ll warrant.

I tell you what I do sometimes for a quick visual, not 100% but it gives you a good idea. When working in Coreldraw or Corel photopaint (this is another reason I love this suite of programs) set up your file at the size you are going to print to, then go into print preview and select A4 page size and see how the graphic wil look because you will virtually be at one to one size.

Allan

[Allan Weyman]

Sorry that should have read ‘Veiwing it at one to one actual size’.

Allan