- Eco Clean wrote:

Plan is to spray paint once I tape the life-sized paper templates over
12x18" plastic stock white boards.

I finally solved the problem, at least one method, although I'm sure
there are plenty of ways to solve the problem set of printing on
a home printer, poster-sized output.

Here are the sample files so anyone can reproduce the effort below.
http://www.fileconvoy.com/dfl.php?id...268090b3 2a7f

Here is one free Windows software method I documented so that others
could try it, and perhaps improve upon it, for the use of everyone who
wants to make a perfectly aligned and matched up poster, without any
guessing, that is larger than what their printer can handle.

There is no guessing in this method, and no editing software is needed.
It seems to work only with image files, but I didn't test anything
other than BMP and JPG image files.

This method takes into account the fact that most printers leave 1/4
inch at the edges.

And advantage of this Rasterbator method is that there is no GUI, per se.
And that it seems to input any desired image file format.

Rasterbator is essentially a printer wizard, where you can print to *any*
sized poster as long as you can calculate the ratio of the actual printer
paper size to the desired final poster size.

A) Download & install "Rasterbator" freeware
https://rasterbator.net & https://rasterbator.net/Download
Described at https://www.cnet.com/how-to/print-yo...giant-posters/

B) Note that Rasterbator units are in metric where I need a 1.4 ratio.
a. US Letter is 8.5x11" which is 216mm x 279mm (Rasterbator uses mm)
b. US sign is 12x18" which is 30.48cm x 45.72cm (Rasterbator uses cm)
c. The ratio is 1.411 sized by width or 1.639 sized by height
(practically, it doesn't seem to make a difference which you use)

C) That means if we let Rasterbator tile by width, we use a 1.411 ratio.
(304.8mm divided by 216mm is a ratio of 1.4111)
If we let Rasterbator tile by length, we use a 1.64 ratio.
(457.2mm divided by 279mm is a ratio of 1.639)

D) Start Rasterbator, choose "English", & press "Continue".

(1/5) Select source image "C:\files\newt.bmp" & press "Continue"
[http://www.flileconvoy.com/dfl.php?i...064faba 60af]
(2/5) Select paper size of "US Letter (216x279mm)" & "portrait"
and press "Continue"
(3/5) Define output size either of
1.4 sheets wide (which shows an "Output image size" of 30.2x45.4cm)
or
1.6 sheets high (which shows an "Output image size" of 30.5x45.8cm)
and a "Paper consumption" of 2x2=4 sheets
Press "Continue"
You may need to click "Yes" on a small-dots-take-longer popup warning.
(4/5) Set rasterbation options
[x]Draw cutout line around rasterbated area
Dot size = 1mm (0.1mm works ok also - but the default of 10mm is too big)
Color mode = (o)Multi-color
Press "Continue"
Note: Best results are when you click the color to choose your
text color and then you set the Multi-color option.
(5/5) Save rasterbation as "C:\files\newt.pdf"
Press "Rasterbate"
Note the advice for printing from Adobe Reader:
"When printing the image in Adobe Reader, choose Page scaling: Fit to
paper at the options window that comes up. If you choose horizontal
paper alignment, also make sure Auto-Rotate and Center is selected.
Most printers cannot print to the margins of the paper - these settings
ensure that all the images will be completely printed."
E) Press "Close application"
[x]Open rasticulate file

F) The file will come up in Adobe Reader as a PDF.

G) In Adobe Reader, press "File Print"

H) In the Print options form, press "(o)Fit" & print it.

I) Tape the 4 sheets of paper together & trim to fit the sign round edges.
Notice that there are trim lines by default, which are accurate.

Caveat: The printing is *exact* so there is zero overlap when you trim.
It's not perfect, but it easily extends to any size poster.