Hello, I’m working on a wall mural. I’ve never designed something so large and I’m wondering what the best approach to this is for when it goes to print and to keep file sizes down.
I’m using photoshop for the file as well as illustrator to create some of the vectors.
Wall size is 156” x 94.75”
Is it best to create the artwork at full size?
What is the optimal resolution dpi I should make the file at for best printing?
Any other tips or suggestions would be greatly appreciated
The first time is always exciting.
Others will probably chime in, but definitely talk to the printer. The printer should provide you very clear specs on how to set up the file and what the minimum dpi should be.
Usually you will be designing at a 1/10 or 1/4 scale. BUT, do not assume that is the case. Talk to the printer and ask them how they need the file set up.
And don’t forget the bleeds!
I should add that we are saying talk to the printer because there is no “universal” right way to do it. Each print vendor has different requirements and different ways they want files set up to work best with their equipment and systems.
Since the wall fits on an Illustrator artboard, work at 100%
You need to talk to your printer AND installer.
You need to specify if your mural is SAV wallcover (self adhesive vinyl) or Paste-up vinyl (sometimes paper) wallcover. This will determine your seam overlaps and bleed. You will want to indicate where your seams will fall.
SAV requires an overlapped seam. It tends to shrink over time and if doublecut like real wallpaper it will open up in a short amount of time. 1/2" usually does it.
Paste up wallcover, I usually give 1/4" to 1/2" overlap on the seam (a 1/2" or 1" total overlap) depending on what the INSTALLER wants. They will double cut and strip out the waste somewhere along that overlap and give you a beautiful almost invisible seam (not necessarily down the center, but they do use lasers to get vertical.)
DO NOT PUT SEAMS THRU TEXT. Especially small text. You can put seams thru very large title text if you have to, but it’s best avoided.
You can just mark your seams with lines in your file and the printer can tile it out for you.
You need to actually go and measure the wall. Your installer may want to go with you. Do NOT trust a client’s dimensions. (frankly I don’t trust designers’ dimensions either and we go measure the wall before printing if at all possible.) While you’re there find out if there is going to be a kick (baseboard) either already in place or being installed after. Also if there is a ceiling that can be trimmed to (don’t laugh, a lot of old factory spaces have walls that stop several feet below the industrial ceilings.) Once you have exact dimensions, you shouldn’t need more than 2" bleed all around, but I usually ask for 2" top/bottom and 6" on the ends. More width if you are just measuring studs without drywall.
A mural at this size would generally run somewhere between 75 and 150ppi at final size. Likely around 100. However, if you have smaller inset photos that are meant to be viewed at arm’s distance, especially if text is involved, you want those to be around 150ppi.
Find out if you, your installer, or the client’s contractor is responsible for priming the wall.
SAV wants a smooth glossy surface (eggshell or better) and the paint has to dry for several WEEKS before you can apply SAV.
Paste-up requires a special sizing primer. It dries in 24hours.
Wall murals are not always installed exactly as they should be. There are a lot of minor variables when things get printed, not to mention variables of the wall construction itself (I once had a wall grow by 4 feet between VIF and install because things got changed by the architect.) If other things require alignment to mural elements, make sure your installer knows this. It’s a good idea to be onsite or at least have a good conversation with the installer before it goes up.
Great info on that, PrintDriver!
That’s probably the most thorough answer you could give them.
Awesome thank you for all this knowledge!!
I’m curious. How would you recommend indicating where the seam should go — a brightly colored line through the image on a non-printing layer, maybe?
I suppose knowing the press’s maximum print width and determining how best to position the seams without creating other problems or raising the cost of the job is important, too, right?
You need to know the width of the media you are using.
Anyone printing wallcover can use the smallest roll width of 54"
There is one paste-up vinyl we use a lot that goes out to 70"
(As a side note, we use the 70" to do horizontal seamless things or to wrap individual panels.)
BUT,
Installers don’t like widths wider than their wingspan. Makes it hard to hang and align. So we mostly stick to 54" goods, printable to 53" and that has to include any crop marks and bleed.
As for indicating seams, TALK TO THE PRINTER.
We like to have the finished-sized panels put in as boxes on a non-printing layer. We’ll also accept lines on a non-printing layer. Doesn’t matter the color of the lines as long as the layer is labeled SEAMS and nothing else is included on that layer.
It helps a lot if the panels are measurable with a tape measure. IE, don’t send me something that is 46.50219990 wide. Make it 46.5"
Sometimes we have to measure out the panel seams on the wall before install if something goes sideways onsite, or if some element in the mural has to be centered on the wall. Keep it simple. 
Oh, yeah, if printing on SAV, you may be limited by your overlam width (paste-up doesn’t generally have an overlam though you can sometimes get a liquid one applied before or after install. Not many printers offer the overlam, but the installer might.)
Many printers only carry the 54" goods for SAV because that’s what most of the lams are. But you can get 60" goods in SAV and lam if you really need to.
Where this is such a small mural, if you want special materials you may end up having to purchase a whole roll of media and lam. Can get spendy. Rolls come 75’ to 100’ +.
A 13’ x 8’ mural only uses about 40’ plus web. Otherwise, stick with what the printer stocks.