CURRENT STATUS, 24 July 2026: Thus far, I have written up the first sections, including making a carrier plate and setting up your Epson SC-P900. I have gotten a few steps further than this in my own work, but I have yet to write all that up. Patience, please!
I’m going through the process of figuring out the right way to set up my photogravure practice using a technique direct-to-plate (DTP), in which you print etching masks directly onto photopolymer plates with an inkjet printer. And if you’re here, I bet you’re struggling like I have been. This is where I am documenting what I’ve learned in the hopes of creating something repeatable that you can use for yourself.
Please note that this document is a work in progress, and is currently incomplete. I’ll update as I go, and your feedback is always welcome!
What are we doing again?
In DTP photopolymer intaglio, you print a positive image directly onto an unexposed polymer plate using UV-opaque inkjet ink. Where ink lands, it blocks UV light during exposure; the polymer underneath stays soft and washes out in water, becoming the ink-holding recesses of the intaglio plate. Where there’s no ink, UV light hardens the polymer into the non-printing relief surface. (You can make relief plates too, but in that case you’d use a negative image, and also all this calibration stuff is probably unnecessary.)
The ink does two things at once: It forms the image and acts as its own aquatint screen. The microscopic structure of the inkjet dot pattern creates the fine texture that lets the plate hold ink in graduated amounts across the tonal scale. So there’s no need for a separate aquatint exposure. (Why direct-to-film processes require an aquatint is something I actually don’t understand.)
Why calibration matters: The relationship between a digital tonal value, the ink density on the plate, the depth and texture of the etched polymer cell, and the final printed density is not linear. Calibration yields a predictable, linear transfer curve so that a particular tone on your screen yields the same (relative) tone in your print.
Why the P900 is cool for this: The P900 can use both matte black (mK) and photo black (pK) at the same time, unlike the earlier P800. MK is the primary UV-blocking ink, but mK alone causes a specific problem on the P900: at certain ink densities, the dithering pattern is too dense, and produces insufficient texture in the photopolymer, resulting in a characteristic light band in the midtones. To overcome this, we’re going to blend three channels: mK, pK, and light black (LK). Each works in a complementary tonal zone, where mK dominates the shadows, lK carries through the midtones via a bell-curve distribution, and pK runs throughout to ensure there’s a halftone in the ink to produce the needed texture, being slightly less UV-opaque than mK and allowing just enough UV penetration around the dot structure to create a robust texture. That said, the P800 can use yellow ink in place of pK, having similar UV properties, but I haven’t tried that personally, not owning a P800.
Materials
Fair warning: This is not a cheap shopping list. You might find you can skip some of this, if you don’t need fully dialed-in results.
Hardware
- Epson SC-P900 inkjet printer (or similar Epson printer that can do thick media).
- Toyobo photopolymer plates, at least 3 or 4. I am using A4 plates to start.
- Access to a 3D printer, or a willingness to cut up some thick matteboard, to make a carrier for the plate.
- A timer, or better yet a UV dosimeter that can measure at 365nm.
- Print calibration tool, like a Calibrite Studio. Not a screen calibration tool (although the Calibrite Studio does both!)
Software
- Official Epson drivers including Epson Media Installer. This will give us the low-level access to the printer that QTR (below) needs, and also let’s us define the dimensions of our carrier so it prints cleanly without destroying our expensive P900.
- QuadToneRIP (QTR). Alternative printer driver. QTR going to drive our printer directly, allowing us to precisely translate pixel grayshades into specific combinations of ink using what are called quad files, which define that mapping. Kinda like a LUT for Epson printers.
- Print-Tool. Printing interface. This is the front-end to QTR, it provides a graphical interface for sending jobs to the printer using QTR’s unique capabilities. It’s also a great tool for printing photos on Epson printers generally.
- QuadToneProfiler-DN V3 (QTP-DN). Quad file creation. This is an interesting bit of software that is enormously helpful in setting up the quad files we’ll need.
- QuadToneProfiler-Target Generator. Optional, but free so why not. We'll use this to generate the calibration step wedges. Or you can just use the one I created.
- ArgyllCMS. Calibration software. We're going to use this in conjunction with our Calibrite Studio to measure the tonal density in our final prints, and feed those results into QTP-DN to get the gamma dialed in.
Process overview
Broadly speaking, we are going to follow these steps to get where we need.
- Make a carrier.
- Establish initial printer settings.
- Print the open bite test image using the premade blocking curve quad file.
- Use this to establish exposure.
- Simultaneously, figure out the maximum level of (inkjet) ink that results in rich blacks without open bites on the plate.
- Create an initial quad file with a candidate pixel-to-inkjet mapping.
- Print a calibration chart.
- Read in and analyze the calibration chart.
- Use those results to create a refined quad file with what is hopefully the final pixel-to-inkjet mapping.
- Possibly repeat 5–7 if the results need further refinement.
- Make beautiful prints!
Make a carrier
Although the Epson P900 has a front loader that can accept thick media directly, we really don’t want the printer touching the photopolymer plate. The rollers will create ugly marks on the plate that will show up in the final print. So we need to create a carrier that will hold the plate, and give the printer something to grab onto without touching the plate directly.
3D print it!
Everything I’ve read is basically: Oh, just cut up some matteboard, but without much in the way of instruction about how to do that. But I’ve got access to 3D printers, and when you have a hammer everything looks like a nail. So I made a 3D printable A3 sized carrier to hold my A4 plates. The Toyobo plates I’m using are 0,73, thick; I made the carrier 1,5mm thick, the thickest the Epson can handle, just because printing thin things is tricky. I also had to make it in 4 parts, because my Bambu P2S doesn’t have a printbed large enough for an A3 sheet. The carrier should be printed in PETG, which is more flexible and more durable.
So, download the files here:
If you have a Bambu Labs printer, use the .3mf file, and print each plate, dusted and done. Otherwise, use the .stl files, load up your favorite PETG, and use the following settings in your slicer:
- Layer height: 0,1mm (necessary to ensure the final height comes to 1,5mm and not more)
- Initial layer height: 0,2mm
- Avoid crossing walls: true (I had to do this to avoid issues with the head causing my print to lift)
- Wall loops: 3 (might not be necessary)
- Initial layer speed: 25mm/s (I had real bed adhesion issues any faster)
- Initial layer infill speed: 75mm/s (same reason)
- Enable support (if possible, use PLA as your support interface material)
Print both Carrier A and Carrier B twice each.
(I had transparent PETG and ref PLA queued up, it really doesn’t matter what color you use.)
Assemble
Now, take one Carrier A, and one Carrier B, and make sure the tabs fit neatly together. Then, use generous amounts of super glue to affix the interlocking tabs together, making sure the parts fit tightly against each other. Do the same for the other A and B. Then take the two halves and do the same for them. One advantage of printing in translucent PETG is you can see the glue coverage, which is helpful. Then, just to be sure, I applied some masking tape on the underside of each joint, which seems to help.
Establish initial printer settings
Firmware and printer settings
Make sure your P900 has the latest firmware installed; you can do this from the printer itself.
Then, on the printer, go to “Settings” > ”Printer Settings”, and set
- Error Notice > Paper Mismatch: Off
- Error Notice > Detect Paper Meandering: Off
- Thick Paper: Off
Now, these may sound counter-intuitive, but the reasoning is…not super clear to me either. I took these settings from Clay Harmon’s P900 set up guide, and I’m going to just take it as good advice. I believe disabling the Thick Paper setting in particular prevents the paper from overloading our custom media type (see below), but that’s just a guess. Maybe Clay Harmon can tell us?
Driver
Download and install the official Epson driver. Don’t skip the utilities, because we need Epson Media Installer too. I know, no one ever actually does this, when Apple’s default printer utilities usually work just fine. But because we need very low-level access to the printer, we have to go through the official drivers. You might want to uninstall the Apple AirPrint driver to avoid confusion. Once you’ve installed the proper drivers, add the Epson printer over WiFi as a Bonjour printer (not as an EPSON TCPIP printer); apparently QTR doesn’t work over USB? Maybe?
Epson Media Installer
This is a great, but weird piece of software that allows you to define custom media and send it to the printer. We need to add a custom media type that tells the printer about the physical characteristics of the plate carrier. And lucky you, I’ve already done this. Download this file first.
Then, in Epson Media Installer, click “import”:
Then, find the new entry, it will be called “DTP Carrier Plate”. If your carrier plate is a different thickness, you can adjust that by clicking “edit”. Then click “Set to printer”:
Where’s the rest!?
It’s in process. You can imagine, writing this all up is time consuming. Actually verifying all the steps is even more so. But I promise it is coming!
Useful resources
These are the resources I’ve drawn upon to make this document. You will find contradictions and incomplete information; I am really hoping the resource you just read above fills those gaps and gives a complete picture.
Online
- Clay Harmon’s blog: clayharmonblog.com
- P900 setup guide
- Original DTP Quick Start. An older process, but still worth reading to get some clarity.
- In the Weeds with DTP. Background on earlier ink-blend experiments, obsolete but interesting
- Downloads. Lots of good stuff, dig around in here.
- Walker Blackwell's description of his DTP setup sequence: photrio.com/forum/threads/direct-to-plate-polymer-photogravure-any-step-by-step-guides.216424. Includes descriptions of his exposure test, open-bite/limiter test, calibration to contrast intent, validation; also describes multi-row averaging targets. Note his ink-channel description reflects his own studio setup, not the QTP-DN curves.
- QTP-DN V3 support site: publish.obsidian.md/quadtoneprofiler
- QTP-DN V3: developingbyinspection.com/quadtoneprofilerdn
- QTP-DN V3 additional resources: go to publish.obsidian.md/quadtoneprofiler, navigate to the QTP-DN V3 documentation, and find the resources download link for
QuadToneProfiler-QuickCurve-DN-Resources.zip - ArgyllCMS chartread workflow: bwmastery.com/blog/2021/using-argyll-cms-to-measure-grayscale-step-wedge-targets
Books
- Printmaking: A Step-by-Step Studio Guide by Jenny Mason-Gunning
- Polymer Photogravure by Clay Harmon
Photogravure: Instruction Manual by Henrik Bøegh