Ever wanted to cover your wall with a nice high-resolution DIY poster? With a little bit of effort and a lot of paper, you can make a high-quality block-printed poster with free, open-source software. This method produces a nice smooth result, without using small dots like other block-printing preprocessing methods.

Prerequisites:

• Inkscape – http://inkscape.org/ (linux, mac, windows)
• PosteRazor – http://posterazor.org/ (linux, mac, windows)
• Source image (medium to high resolution; jpg, png, etc.)

Once you have installed all of the above programs, continue on to the following steps.

1. Vectorize

First, open up Inkscape and import your raster image. Then go to Paths->Trace Bitmap. You can mess with the settings in this dialog box, but I would advise sticking with a low pass count if you want the outline of an image, or a high pass count if you want more detail. If you aren’t getting good results, try using VectorMagic, then import your resulting .svg into Inkscape.

After tracing your raster, delete the raster item so only your vector trace remains. Select the vector (drag a box around it), and click export. Choose a resolution based on your print size, I’ve had good results with 60dpi. Keep your image under ~25M, if it is larger, it may cause problems in the next step of the process.

2. Slice and Print

After you have exported your raster, open up PosteRazor. Select your exported png file, and click next. If your file is a reasonable size, you can now choose how many pages you want to print. If your file is too large, the program will crash. Go back to the previous step and reduce your resolution.

After going through the PosteRazor wizard, you should have a PDF file that you can print out. PosteRazor does a good job of scaling your image, even if you didn’t export at very high resolution.

3. Tape and Place

Junky laser printers that are nearly out of toner can really make gradients look odd...

Print it out, tape it together, and you have a nice block poster! There are several taping methods that may work for you:

• Taping together blocks of 4 sheets, or larger squares and tape these to a wall
• Tape individual pieces of paper to the wall
• Tape all pieces into blocks, then assemble blocks into poster, tape, and hang

I’ve found that hanging blocks of 4 sheets works quite nicely, and allows you to adjust for any bad taping jobs, if needed.

Feel free to drop a comment if you have any questions or suggestions.