The amount of dots in an inch of a halftone is determined by the LPI, also known as line screen. The higher the LPI, the more dots there are per inch. A higher LPI means the dots are smaller and less noticeable. Letterpress printers typically use between 85-133 LPI for their halftones. We find that 100 LPI is a good choice for all plate types and is the default we apply if you don’t specify.
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What is a grayscale and a halftone?
The technical definition: a halftone is a matrix of different size dots which allow printers to simulate tonal variation when printing with a single ink on press. What this means: a halftone allows you, using one color ink, to approximate various shades of color. Take a magnifying glass and look at a black and white photo printed in your local newspaper. You’ll notice the image is actually made up of different size dots. The smaller the dot, the lighter the color in the halftone. A grayscale is made up of pixels that are in varying shades of black so the tones are represented by the different shades. Once a file has a line screen applied, the grayscale is now a halftone.
Should I gang up my images/smaller files into one larger file?
If you are ordering printing from us, no. Please send individual files and we will set up for most efficient production in our shop.
If you are ordering plates and doing your own printing, yes! By ganging up the plate yourself, you have more control over the margins and gaps between the ganged up artwork. Between each individual piece, we recommend .375” for plastic-backed plates and .5” for steel-backed plates. Our negatives come out of the imagesetter in 18″ strips, so ganging up onto a 17” wide strip, and up to max 22” long, is the most economical way to make negatives. Since we like to keep our maximum plate size at 17 x 22, please break larger files into two files.
That said, if you were to send us many individual files, we’d gang up the pieces in the most cost-effective manner. If you’re using plastic-backed plates, after we gang up your files, we’ll ship your job as a single plate and you can trim them easily yourself, using scissors or an Exacto.
If you’re using steel-backed plates and we gang up your files for you, we’ll ship your job as a single plate, unless you provide a cutting diagram for us. If you are submitting a ganged up file, keep in mind the fingers of our employees who have to trim your metal plates and leave us enough room around your text/images to hold the plate safely while we cut.
What programs do you support?
Our favorite ways to receive files for letterpress platemaking are by you sending us a press-ready PDF file (with fonts embedded) for platemaking. This PDF will serve as both your hard copy and your plate file. No additional faxing or email needed.
Our second favorite way is for you to send an EPS or AI file for platemaking. We also accept PDF digital files in current versions of other major design programs (i.e. Quark, InDesign, Freehand).
If you are creating your files in Photoshop, we like to say that this program is good for images but not so great for text. It’s best to convert your grayscale images in Photoshop and place them into Illustrator where you will add your text. If Photoshop is your only option, start with a file that is 600 dpi minimum so you can minimize the pixelation of your text when you convert files. More on file conversion to Image Mode of Bitmap under File Prep Tips. We prefer tif files from photoshop for upload.
Note, we can often make plates from PDFs created from Word files, however, Word is not able to format your file exactly the way we need. So please tell us your file was originally a Word document so we can anticipate and make corrections. If you are designing in Word, we suggest that you don’t use any funky or crazy fonts we won’t have access to. Oftentimes, they will just print as strange characters. Your images placed in Word will usually require some corrections too. You can email your files to plates@boxcarpress.com for an evaluation first and we’ll advise on how letterpress friendly it is.
Can you scan my camera-ready artwork?
Yes! Simply mail us your camera-ready art and we will scan it in for you. When possible, we love art work that’s on smooth, bright white paper or drafting vellum. Textured paper makes our job more difficult as the scan will pick up any background patterns, paper shadings, paper texture, etc. We are faithful to originals: if you require modification or retouching, you may be charged for additional file preparation time at our shop rate of $60/hour. We’ll contact you before we bill for additional file prep. We can scan, in house, artwork up to 12 x 17 inches.
What’s the largest size plate you can make?
For the 94FL, KF95, KF152, and 152SB plates, the largest size plate we can process is 17.5” x 22.5” (where your image area is 17” x 22”). For all other plates, the largest size plate is 16” x 22” (image area is 15.5” x 22”)
What’s the thinnest line and smallest dot you can hold on a plate?
It depends on the plate (though no hair lines, please!). If your plate has a 94 or 95 in the product name, we recommend at least a 0.25 point thickness (or larger). If your plate has 145 or 152 in the product name, we recommend at least a .35 point/.007″ thickness (or larger). Watch out for typefaces with swirly curves that thin or have breaks or fonts with fine cross bars.
For dots, we recommend at least a 1 pt diameter if your plate has a 94 or 95 in the product name. Boost that to 1.25pt diameter for plates that are 145 or 152 in thickness. Each of those dots has to stand on it’s own on the plate and that thickness will provide the support at the base of the plate to hold the dot. Watch out for typefaces where the dots on the “I’s or periods are small, as seen in many sans serif fonts that are decorative, free form or look hand drawn.
Undersize lines and dots may appear on your plate as wavy or be missing completely so checking this is very important for a good file and usable plate.
What’s the smallest type size you can hold in your platemaking?
This question is not as straightforward as it seems. We can hold a 3 pt. Times New Roman type face on 94 and 95 plate material but the real question is the next one about the thinnest line and dots the plates can hold. The font choice and characteristics of the font may limit the point size.
What’s the biggest problem that printers new to photopolymer encounter?
Photopolymer plates offer an way to letterpress print extremely detailed designs with a deep heavy impression (or a kiss impression if you’re so inclined). The chief problem that new photopolymer users encounter usually deals with roller height/roller condition. But no worries! Unlike larger problems like war or global warming, roller issues do have concrete and relatively easy solutions. We recommend rubber rollers and, if using a platen press, solid trucks. If switching from lead type/magnesium plates, you’ll want to keep a much closer eye on your rollers. You may find our general printing FAQ’s useful, especially if you’ll be using a Boxcar Base.
What do I need to be able to letterpress print with your photopolymer plates?
You’ll need:
- a printing base. The polymer plates we create aren’t type high by themselves. They need to be mounted on a base to make a type-high printing surface. We recommend our Boxcar Base system. Letterpress printers also use magnetic bases from Patmag or Bunting. If you are printing on a DIY press such as L Letterpress, please refer to this tutorial.
- a Printing press. Remember that most letterpress printing presses people purchase will not be ready to print beautifully right away and a little tender loving care will be needed. Be prepared to purchase new rollers or do other maintenance on your press!
- Ink. we recommend Van Son rubber-based letterpress inks, which you can order in any uncoated Pantone number! Or you can purchase the Van Son base colors and mix your own colors. View the inks we carry.
- various pressroom supplies, including printers furniture, quoins, tympan paper, type gauge, ink knife and (if using a platen press) Kort gauge pins or Henry gage pins.
- a fashionable printing apron
We now sell letterpress starter packs, which contain a lot of what you’ll need to get started.