Boxcar pixelization problems, or am I just being too anal?


I ordered my first pp plate using a bitmap image (I know, I know… it’s not the ideal way, but I wanted to give it a try) and I wanted to get some other opinions of the quality of the plate.

I created the file in photoshop,1200dpi, saved as tiff. Sent the file off to boxcar along with a pdf for a hard copy, and my first thought upon receiving the package was HELLO PIXELS!!!

I gave it a shot on my press anyway, and was quite bummed by the results….

Reading left to right you’re looking at:

1. A penny so you could see the level of anal-ity I usually operate at.

2. The file I provided,

3.The proof from boxcar,

4. A print from my Kluge on lettra 110 (please ignore the slight over-inking, once I saw that the pixels still showed I called it a day)

I don’t have an image of the plate, my scanner just blurs it out but the pixels are really quite visible to the naked eye.

I have to say, I’m dumbfounded by the amount of pixelization present given the 1200dpi file I provided. Why would they even suggest providing such a high-res file only to have the output be so low? Did something get mixed up along the way?Or am I just being too particular and this is just what we have to deal with when working with a bitmap on pp?


Thank you!

P.S. I have contacted Boxcar, they said everything looks good on their end, but something in me just can’t accept that this is the best pp can do.

Log in to reply   21 replies so far


The word you’ve entered isn’t in the dictionary. Click on a spelling suggestion below or try again using the search bar above.


A few questions for you. Was this artwork originally scanned in for output or was it made digitally?

If you look at the original bitmap you can see the same shapes (pixel) printed on your sheet. Lettra is calendared, however, since it’s a fibrous sheet the ink may tend to bleed if your ink to plate is not correct.

I would suggest use Adobe Illustrator for your typography and design that is output for plates. Illustrator will let you Live Trace your high res black and white art that is either scanned into the computer or created in Photoshop. I’ve used this for years and have not had any problems with plates unless the image was low res or the original artwork was rastered.

Casey McGarr
Inky Lips Letterpress
Jonesboro, Arkansas

Why are you starting with a bitmap image though? I’m assuming this is a font rather than free art.

Casey when I looked at the image it looks like there was some rasterizing that happened.

Boxcar probably outputs film at 2540DPI or higher. They also likely output halftones at 100LPI which is the resolution that a photoshop tiff file would output at. If you don’t want pixels, use vector images.


I have to agree with Sumner. Vector images are a must. A bitmap image will always come out like that. The rip sees bitmaps as rows of pixels. Now if your bitmap was generated at 2540 it would alleviate the problem. Once you render a bitmap if you change the size you are just changing the size of the pixels. That’s one of the advantages of vector versus raster images, with vectors you can infinitely adjust the size in illustrator while raster images are the size they are and shouldn’t be adjusted past a couple percent up or down.

Can’t find this in the dictionary!


Pixelization and Rasterizing are Printing Technical Jargon

Rasterize: Definition: The process of converting a vector image into a bitmap image (for letterpress purposes a NO-NO)

Pixelization: is an effect caused by displaying a bitmap or a section of a bitmap at such a large size that individual pixels, small single-colored square display elements that comprise the bitmap, are visible to the eye.

Stanislaus: Get a new dictionary.

My two cents on the issue:

I don’t understand why people are telling you raster images are a no-no for letterpress. Of course vector based images are better and you have already conceded that. Your question is—correct me if I’m wrong—why is there a breakdown in image quality between your 1200 dpi image (which you think looks fine) and your plate, correct?

Depending on the process and qc used in making the plate, there can be a breakdown in image quality, but this will not occur as pixelization: As Sumner stated, most imagesetters output at 2500+ dpi so they can comfortably handle your file.

I disagree about Sumner’s statement that They also likely output halftones at 100LPI which is the resolution that a photoshop tiff file would output at. Holly submitted a bitmap image, a purely monochromatic file that would not be translated into a halftone pattern. The pixel data would be interpreted by the imagesetter and output accordingly.

My main point is, perhaps your file doesn’t look great, but it shouldn’t look any worse on press than it does on the computer. Small detail may get eaten up during exposure, and reverses may fill in because of improper inking and impression, but the film and plate should not be any more pixelized than the file you used, unless you worked at a higher resolution than the imagesetter used to output film (which you did not.)


Casey & James: This is an illustration I made, not a font or clipart. I decided to give bitmap a try since in the past when I’ve converted illustrations to vectors I feel that it loses a bit of the hand-drawn quality that I’m going for.

Paul: Thanks for the two cents! You’re correct about exactly what I’m asking: Why the breakdown in quality? I’m not too knowledgeable on what happens on the plate making end of things, so this helps!

Does anyone have some advice on what my next step of action should be?

Has anyone out there has experience with boxcar specifically and had a bitmap image come back as a usable plate? If so could you post a picture so I could see the level of quality I should expect? I’m finding hard to find one on my own.


The hand drawn quality you are looking for requires grey-scale. This is a problem.

To get the “best” out of the PP you should be using vector images.

Bitmaps get too touchy to deal with when it comes to simple resizing and manipulating.

Bitmap = pixels
Vector = smooth edges

I can’t really tell from the image you’ve posted if there is a breakdown of quality. If you can upload or email me a higher-resolution file I could maybe be of more help.

Douglas et al, digital files are always rasterized at a certain point even if in vector format. Holly is happy with the degree of pixelization apparent in her design at 1200 dpi and is wondering why her plate has a more exaggerated degree of pixelization. I feel like the only one in this conversation who does not think the problem lies in the fact that she started with a bitmap, can someone advise me otherwise or am I correct in thinking that most answers are not actually responding to her question?

Holly, just to confirm, the file you sent to Boxcar was a bitmap TIFF, not grayscale, correct?

I’m with modernman here. A well prepared bitmap at 1200dpi should be indistinguishable from vector. Everything gets rasterized at output anyway.

Without access to the original bitmap, it’s hard for me to diagnose. The Flickr image seems to contain some edge artifacts that could contribute to the poor quality of the final print, but that may be introduced in the JPG process or the upload.

I agree, it should work. I responded likewise on the letpress list.

Vector artwork rasterizes at the selected resolution of the output device, which traditionally is an imagesetter operated at 2540lpi or 1270lpi.

It has always been my understanding that a good quality bitmap tiff with an effective resolution of 1200dpi should look as sharp as vector art. I’ve used this in offset printing countless times with no problem.

If she had sent a grayscale file, Boxcar would’ve either asked her what linescreen to use outputted it with their default recommended linescreen, and it doesn’t look like that is the issue.

I wonder if the problem is with the PDF? They suggest using the “High Quality Print” preset, you said that’s what you used. I think that’s what I used. “High Quality Print” defaults to certain kinds of compression such as CCITT Group 4 compression on Monochrome Images. According to Adobe, “Group 4 is a general-purpose method that produces good compression for most monochrome images.” That doesn’t sound very promising to me!

It would be helpful to see the film. Also, as suggested, maybe have the film made yourself from a local vendor. Then you can see if there’s a problem there or not. If the film looks bad, there’s something wrong with the scan or the way it’s being released (PDF in this case). If it looks good, then there’s something funny going on in the platemaker, but that makes less sense.

If there is a breakdown occuring it has to be during film output, not platemaking. Non-pixelized film can’t pixelate a plate.

Thanks for the enlightenment! All dictionaries are not created equal. Merriam-Webster has no entries for this “Printing Technical Jargon.” Again I put on my orthopaedic shoes and stand corrected!

Even if your drawn image is scanned and opened in Adobe Illustrator and the filter Live Trace is used to convert it to line art, it should hold the points that make up the hand drawn effect. I’ve used this several times when my wife illustrates for wedding invitations and I print on one of my presses.

Next plate you have output use Live Trace on a small Raster Image for a test.


It appears to me that Boxcar gave you back exactly what you should have expected. You need to clean up your images before you send them to the plate processor.

If you scan an image, scan it at 1200dpi in grayscale. That will allow you to take advantage of Photoshop’s many, many filters and options for cleaning up the lines. Once this is accomplished, change it to b/w bitmap (50% threshold), save as tiff, output as PRESS QUALITY PDF (for imagesetters).


Modern man: Thank you, that would be a great help to get a second opinion. I’ll private message you through BP to get your email.

Andy: I did save it down a little bit to upload to flickr, and honestly, I don’t have the best scanner so I understand that it’s a bit hard to tell. I’d love to send you the higher res file too for a third opinion!

Widmark: They ask for the PDF in lieu of faxing a “hard copy”. It’s not supposed to be used for printing (or at least that’s how I understood the instructions) so the quality of the PDF shouldn’t be an issue.

Just to clarify for everyone, here’s my workflow

-scan @ 1200dpi grayscale
-open in photoshop
-adjust levels/clean up image
-convert to bitmap, 50% threshold
-save as tiff, no compression
-save as pdf for hard copy

from the boxcar website

“When submitting your file, send us a hard copy of your file! Our favorite ways to receive files are by you sending us a press-ready PDF file (with fonts embedded) for platemaking and faxing in a hard copy for the proof. Our second favorite way is for you to send an EPS file for platemaking with a press-ready PDF for the proof. A hard copy allows us to guarantee the quality of plate, ensure that files are accurate, and that the plate will match what you are expecting to print. A hard copy allows us to avoid file problems, such as lines that don’t hold, text that has moved or been cut off. “

I went for the second favorite way, with a TIFF instead of an EPS. But now that I’m reading it again I’m really wondering if they just used my PDF. When I compare the plate to my PDF it matches pixel for pixel, which I did mention to boxcar when I called, but they insisted that was not the case. But they also said that their proof looked ”perfect” so….

I’m starting to think I should just send a press ready PDF and fax a hard copy so they only have ONE file to work from and try again.

If you sent a TIFF and a PDF you’d expect they’d print from the TIFF but that’s not always the case. I’m always very careful to name my files, but generally almost everything I release for offset or letterpress is a press quality PDF (or pdfx1a for offset).

But I’ve still had big commercial printers send me hard-copy proofs clearly made from a PDF I sent them called “PDF for layout reference only, DO NOT PRINT

As a means of clarification, lets discuss DPI. Most continuous tone images, Photoshop photos, are saved at 300dpi. Type at this resolution will look like crap. Line art for type and drawings at 1200 will look okay but is at the low end. High end image setter used in the 80s, 90s and today would do 1270 dpi or 2540 dpi. 2540 is the highest necessary for very sharp type and drawings. If you enlarge it 500% you will see smooth edges to every letter. Saving as a Tiff (Tagged Image File Format) or EPS (Encapsulated Post Script) file format will save at the high resolution, the difference being that EPS saves with a low res screen preview while a Tiff is at the same resolution for on screen preview.

Saving as a PDF as Widmark said must be done with the correct setting. Print ready retains the resolution while on screen preview is just that, low res the same as your computer, either 98dpi on PC or 72dpi for Mac.

On another Forum, this same discussion brought a response form one reader that he always supplies scans at 6000dpi but he corrected that to 600, twice the normal resolution for image files. Holly, normally 1200 should be good enough for photo polymer. Perhaps Boxcar made an error. Talk to them, Kyle is very good about responding and trying to correct problems.

hollyhanna: Boxcar says its second favorite way is to receive an EPS file with a PDF. But a TIFF->PDF file isn’t the same as an EPS->PDF file in terms of quality on the printed page. We used to rely on TIFF files almost exclusively for our graphics until we saw the better results we got with EPS->PDF files. Some places use TIFFs for small images. We want clarity in all images so we don’t use TIFF’s any more. Nor any JPG->PDF either. Send a non-job dependent EPS->PDF file to Boxcar & see the results for yourself. Good luck. - j archibald