June 2009

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More Sun Printed Vandykes

Posted by on 24 Jun 2009 | Tagged as: Vandyke Brown

Two more vandyke prints from the Trees series. Printed again with sun on top of inkjet toning prints.

Jalo Porkkala: The Brännbäck Pine Tree, pigment toned Vandyke brown print.

Jalo Porkkala: Saarineva Forest, pigment toned Vandyke brown print.

Pigment Toned Vandyke

Posted by on 20 Jun 2009 | Tagged as: Vandyke Brown

We finally had a sunny day, and I promptly used it for Vandyke printing (but it’s raining again when I’m writing this 🙁 ). I had already made some inkjet negatives and underlying toning prints, so I was ready to go whenever exposing with sunlight would seem possible. I wanted to try printing at home, where I don’t have a darkroom or UV exposure equipment, so I need to use sunlight and simple basic techniques.

Here is the image that I wanted to print in vandyke (left) – it has been cropped, and minor adjustments made. Next I desaturated it, discarding the colors.

After curving the image (with a pre-constructed correction curve) I inverted it to negative and flipped horizontally. After filling it with green UV blockin color (R96-G229-B0) I printed it on transparency film. I also made a colorized version of the image (right). This I printed, as the underlying “toning” image, on the paper to be sensitized with VDB.

My goal here was to achieve a final print with a split tone effect, with warm shadows and cool highlights. My chemistry is the standard VDB chem, with the recommended workflow – details can be seen e.g. at AlternativePhotography.com.

Jalo Porkkala: The Ahlstrom Oak, pigment toned Vandyke brown print.




Pigment Toned Vandyke Brown

I put online a small video of making this print, you can view it on YouTube.

Summertime Browns

Posted by on 16 Jun 2009 | Tagged as: Vandyke Brown

I thought I’d try Vandyke Brown (VDB) printing with the sunlight as a minor summer project. My first (quite easy-going) tests with digital negs proved that the UV blocking color from the previous vandyke sessions (R:255, G:15, B:15, see the post from 20 Dec 2007), using a metal halide lamp, will pass some UV light through the densest areas of the negative, thus leaving no paper white, that we want as the lightest tone of our print. So I had to do some new tests, and this time I came to choose a green hue (96-229-0).

vdb_sun_block_test-2
Finding the best UV blocking colors on darker red, yellow and green portions of the color chart, printed with an Epson Stylus Pro 3800. The selection of the most suitable colors form a heart-shaped pattern on the right.

I also looked for my standard print exposure that would always be the same. Naturally the printing times in the sun will vary according to daily UV levels. My exposure meter will be a Stouffer 21 step wedge, exposed on a VDB test strip. I expose the material until I can barely see the step #12 differing from paper white. After the wet process the print will darken, normally up to step #16 with my chemistry and paper.

Thought I’d also try toning VDB to different colors. The customary way of toning silver images (which a processed VDB basically is) is with noble metals (gold, platinum, palladium), before fixing the print. But this time I will try to make Epson printer inks produce the colors. The idea is to print the “toning print” with the inkjet, and then the vandyke print on top of that. I am using Epson UltraChrome K3 inks that are both durable and waterproof. I imagine the advantage over the traditional method is the possibility of using wider range of colors, and easily generating split tone and multicolor effects.

Two toning test prints from an Epson 3800. The images are blurred with Photoshop’s Gaussian Blur filter to make registering the Vandyke negatives easier.

VDB test prints from a colorized (green) negative on top of the toning prints above. The goal here was to get a view of a “cold tone” and “warm tone” Vandyke prints.

ImagOn Screened

Posted by on 11 Jun 2009 | Tagged as: Polymer Gravure

When kicking around ideas of different uses for ImagOn polymer film we decided to try it at printing photographs that were screened in Photoshop. You can find info on this topic and the vast possibilities of ImagOn in Keith Howard‘s books Non-toxic Intaglio Printmaking and The Contemporary Printmaker: Intaglio-Type & Acrylic Resist Etching.

Here we have a quick experiment; we first created a tone compensation curve, and then applied it to any grayscale image to be screened and converted to bitmat mode for outputting to an inkjet printer.

An ImagOn test print and a plate. Note the open bite that occurs at the darkest tones – the screen frequency is too high, or the printer is outputting too much ink (for this purpose) so the light cannot pass during the exposure.

The curve can be created for halftone screened images as well as for continuous tones (again ChartThrob does a good job here), but when using ImagOn and inkjet technique we tend to clip the tones somewhat, especially at the dark end of the range.

Our curve for Andromeda’s EtchTone screen at 85 lpi frequency. The curve is very straight, it is messed up by open bite at the darkest tones. Actually the curve we finally used was adjusted by just straightening it to the left edge (the gray line).

Besides Photoshop’s own (actually quite good) dithering methods there are other software tools for screening images. Some of them work as Photoshop plug-ins, accessible from the filter menu, for instance.

steeletch-screen1
Enlarged portion of a bitmap image showing the EtchTone’s SteelEtch screen.

Depending on the chosen screening technique, the outcome can be finely dotted screen, almost invisible to the naked eye, or coarse special effect, breaking the image surface down to larger dots. We tried Andromeda Software‘s EtchTone plug-in (among others), finding it quite interesting but hard to control – with the inkjet technique and our line frequencies we couldn’t get rid of posterization, which showed annoyingly especially on some tone gradients.

An ImagOn print from a plate exposed through a screen film positive. Notice the heavy posterization in the sky area.

We are done with testing ImagOn and other polymer plates for now – some of the students are experimenting on their own – maybe we will hear from them some day…