Peter J. Blackburn has found his favorite gum bichromate paper. One that he used to shun. And one that needs no sizing.
Gum printing for me began in 1988. From the beginning, I ignored the advice of many gum experts to use toxic sizing by searching for ways to print bright, crisp gum prints on unaltered paper.
“BFK Rives was the very first paper I explored. The results, as I recall, were mostly unsatisfactory. Poor contrast, dirty highlights, blocked shadow detail, and dull colors seemed to plague every print.”

But other papers brought the same disappointment. And the temptation to experiment with hazardous formalin grew greater with each printing failure.
Alkyl Ketene Dimer
Fabriano Uno and its sizing, alkyl ketene dimer (AKD), literally changed my gum work overnight. Ever since I have religiously sought out papers incorporating AKD. Today, there are a myriad of AKD paper choices available for the gum printer. Indeed, all of my gallery work to this date has been created on AKD papers, and most of my portfolio images, too.
Suddenly BFK, Again!
Then last year, I stumbled upon a new twist in the gum printing road. My wife, Anne, is an artist who also teaches high school art. One day, she brought home a batch of student artwork to grade. Most of the images were rendered on BFK Rives. The work, woodcut and linocut prints, was quite good.
Ah, BFK Rives. Gorgeous BFK Rives. Oh, how I longed to make a wonderful gum print on this paper. Just one measly print! But jarring alarm bells and cockpit warning voices began exploding in my head.

“Warning! Toxic sizing ahead! Pull up! Toxic sizing! Pull up!”
Indeed, the general consensus of the gum literature either advises against the use of BFK Rives or recommends treating BFK with liberal slatherings of unhealthy chemical size.
Once again, ignoring the well-intentioned experts, the sirens, and the flashing lights, I gave BFK one last chance. To my delight, Anne had a few sheets of BFK Rives tucked away for her own art.
I just couldn’t resist. Oh, how I wanted to make that paper perform just as it was, right out of the package. So, I swapped a sheet of my then-current workhorse, Canson Heritage, for a slice of precious BFK. Next, I quickly found a few previously printed negatives to use as a test.
Off to work I went in the same manner as my AKD papers, such as Canson Heritage or Strathmore 500. That is, I did not add any supplemental size. No formalin, no glutaraldehyde, no glyoxal. Not even a smidgen of nuclear waste or biomedical debris. And to my mind-blowing surprise, the gum prints on BFK rendered just as if they were printed on those AKD papers!
Huh? How could this be? It must be a fluke of some sort. Have I entered the Twilight Zone? Not finding Rod Serling* I printed more. And then many, many more!
Paper Sizing is Only One Part of the Printing Equation

To this date, I have printed scores of tricolor gum and casein prints on BFK Rives with no added sizing. The contrast is crisp, while subtle detail is clearly evident. Colors are bold and vibrant. Whites are clean. Every print brings new amazement! Unsized BFK Rives is now my primary paper for gum and casein work. And it is a joy to use.
What can be said is that my working methods today bear no resemblance to how I operated at the very beginning. My negatives are different. I use different gum arabic and completely different pigments. Even my exposure techniques have significantly changed.
Toxic Sizing: Can It Be the Exception and Not the Rule?
I’m sad to read how the toxic triad is still readily recommended, even prescribed, for dichromate printing. Perhaps artists should seriously reconsider this matter and only use toxic sizing as a last resort. Dichromate is dicey enough. Adding hazardous sizing only exacerbates the issue.
Find better ways to utilize the sizing already embedded in the art papers you purchase.
Check and double-check every aspect of your working methods.

Many gum printers seem to use toxic sizing to enable the application of many, many layers for building tonality. But from what I have seen, every layer only lowers contrast and blocks shadows. What is labeled as long tonality by some, I call flat, hazy, and lifeless. And the color is almost always muted. It seems to be a lot of work, expense, and hazardous duty for little, if any, return.
However, if you prefer to have flatter, hazier tones, and muted colors in your images, those qualities can easily be rendered on BFK and AKD art papers, too, without being so toxic. Just adjust your negatives and your working methods.

A tricolor print on “unsized” BFK Rives. No muddy, misty colors here.
Just one more point. Consider cutting down on the solution percentage of your dichromate. At present, I only use a 3% potassium dichromate solution as my sensitizer, with an emphasis on the potassium version!
But make no mistake. BFK Rives is readily capable of bright, vibrant gum bichromate images right out of the wrapper.


*Rod Serling is the Emmy Award-winning creator of the hit television series, The Twilight Zone. Without his creative genius, The Twilight Zone would not be a term that cultures everywhere have now appropriated for the surreal and the unexplained. Indeed, when BFK Rives inexplicably printed my images as if being an AKD paper, I wondered if Rod Serling had come back from the beyond to haunt my studio.