Cyanotype Toning with Avocado Stones

Cyanotype Toning book by Annette GolazClive Pigott tries out Annette Golaz’s recipe for toning cyanotypes with avocado. The original recipe can be found in Annette Golaz’s book Cyanotype Toning alongside many other recipes.

Writer and photography / Clive Pigott

I was first introduced to alternative and historical printing techniques back in the early 90’s, when I was in my late 20’s. I had picked up an anniversary copy of the British Journal of Photography which had an article about the history of photography. At the time I was living in Manchester, and there was a darkroom open and available to amateurs.

“They ran an alternative printing day. I don’t remember much about it except I knew then that making a large negative from a 35mm was not going to be a simple thing. As a result, I did not go further with it.”

Cyanotypes toned using avocado
Figure 1: Cyanotypes after toning with Avocado and dried for 24 hours: key to each below:
Cyanotype no tone Avo tone – no additive – boiled egg water
Avo tone – Citric acid – Boiled egg water Avo tone – Sodium Carbonate – Boiled Egg
Avo tone – Citric Acid – Rainwater Avo tone – Sodium Carbonate – Rainwater
Avo tone – Vit C (1g) – Rainwater Avo tone – Vit C (2g) – Rainwater

Interestingly though, I kept a coated sheet of paper from that time, and quite amazingly was able to get a print from it in 2021.

In 2020, I took the notion to revisit alternative photography. I started reading articles, finding various websites and purchasing books. I had already revisited film photography and was enjoying the hands-on ‘craft’ that analogue offered. For me, the creation of a print by hand is hugely rewarding both mentally and emotionally. Thus moving to alternative processes has been a great addition to my favourite hobby and pastime.
It has been a fun and rewarding journey. At other times very frustrating. For example, sourcing and building a satisfactory UV lighting unit to allow flexibility when I could expose the images, proved very annoying at first. The lighting was either very expensive and difficult to get, or relatively cheap and prone to breaking. Being based in NZ does mean that getting hold of equipment and resources is either impossible or super expensive.

My first forays for cyanotypes needed exposures of around 40 – 60 minutes. I battled on this way until I came across a ‘Large Format Friday’ YouTube clip with Mat Marrash – he offered up a game-changing alternative with easily sourced bright UV LED strips. I built an exposure unit from a few ‘hacked’ banana boxes and some papier-mâché. Exposures for cyanotypes are now down to 6 minutes +/- , and gum bichromates are down to 1 minute.

Since 2020, not long really, I have improved what I do though I’m nowhere near a master practitioner.

“I have reached a happy place with it. My workflow is constantly evolving, and it is still frustrating at times, but the success rate has definitely improved.”

Key points that have helped me:

  • Note-taking in a book and on the back of each print, as well as using OneNote.
  • Planning processes before undertaking the work.
  • Re-reading, re-reading and re-reading the reference books. Small nuances often got missed but as problems arose going over the texts again and again allowed improvements and adjustments to be made.
  • Being open to making mistakes – enjoy the journey.
  • Being open to learning from these ‘mistakes’.
  • Sticking to a system/being systematic in my approach and then adjusting one thing when change is needed. I think this is more satisfying than accepting serendipitous results (these are fine in themselves but being deliberate in approach, for me, is more rewarding).

Why tone cyanotypes?

The simple answer is why not? Cyanotypes are beautiful with the array of blues that are possible, but the fun doesn’t need to stop there. I think luckily Annette Golaz’s excellent book on Cyanotype Toning came just at the right time. I had done a few half-baked attempts with stewed tea and wasn’t enamoured with the results.

“Annette’s book added structure and meaning to the toning idea and provided excellent guidance to experiment.”

Annette Golaz’s book in combination with Christina Z Anderson’s fab Cyanotype book were pleasures to read and are key reference guides, and thoroughly recommended for anyone seriously looking at getting into this corner of photography.

Why toning cyanotypes using avocado?

That’s a good question.

There are heaps of botanicals that can be used, and all provide very interesting tones. However, a small passage in Annette Golaz’s book stood out where avocado stones were described as making beautiful tones but were hit and miss, and therefore were not described in detail. But because the toning created greys, I think I was intrigued, and so decided to have a play with them.

All the other tonings I had made before were from botanical powders and seeds purchased specifically for the purpose whereas the avocado stones were a ‘byproduct’ of a fruit purposefully bought for eating and would normally be disposed of – I therefore liked the idea of making use of them.

Pre-toning process notes

I will not go into specifics here. All my work processes for cyanotypes have been acquired from the excellent reference material written by Malin Fabbri, Christina Z Anderson, and other references/authors found at I have developed my workflows from them. My notes, therefore, indicate some personal adaptations as to what works for me.

Digital negatives

OHP sheets that are inkjet printable are often US letter-sized. I tend to make two negatives per sheet, for economy. I contact print these onto the paper cut to 8 inches by 5 inches.
In Photoshop I often add text to the negs (eg names, ‘cyanotype’, version number).
Also, in Photoshop I set up ‘actions’ to speed things up and prevent me from having to remember what to do when I make a new neg.


  • I cut my paper.
  • I buy large sheets from my local art shop. They hold good stocks of Fabriano Artistico and Canson Montval – these are my ‘go-to’ papers, and luckily, they work well for all the alt processes I have fun with.
  • I use a lightbox to measure the print area for each print. I place a negative on the lightbox, place paper over the top, and draw each corner when aligned to my liking over the paper. I then join the corners. I use a pencil.
  • I label the reverse of each sheet with the name of the image and the process it is intended for, together with the paper type and size. Before coating with chemicals, I note the date and what I am coating with, and the volume used (e.g., CC 15/10 1:1 | 0.6ml | 2 July 2023).
  • I use the classic cyanotype formula at 15% FAC and 10% PF w/v.
  • I make it fresh almost every time and in small batches. For ease of measuring the chemicals, I make 10 mL.
  • I use a Hake brush and always pre-wet my brush in warm water and then squeeze that out before painting on the chemicals.
  • I add approx. 0.6ml to the print area using a plastic dropper and paint inside the lines drawn (as described above).
  • I always coat an extra sheet for use as test-strip
  • I then Air dry it.


  • Expose a test strip (my set-up leads to a rough estimate of 7 minutes). I judge final exposure on this. My timings are rough. I am usually on full, ¼, ½, ¾ of a minute (e.g., 6mins 45 seconds).
  • In standardising my cyanotypes, I now ‘develop’ for 7 mins in citric acid water, then another seven in fresh water, then 7 more in a third bath. First two baths often start tap warm. I use a timer to avoid over-development (and finding a pale washed-out image).
  • Air dry again.

Avocado stone toning

Collect and store

  • I acquire my stones from anyone I spot cutting an avocado, and about to biff out the stone.
  • Do not air dry them – they shrink and go really hard, making them not much fun to cut.
    Instead, I recommend using them fresh, freezing them whole or chopping them up into small bits and then freezing them. I have not undertaken a full study as to whether the freezing is detrimental. However, my recent tonings used for the purposes of this article were with frozen chopped and non-chopped stones and I am more than happy with the results.
  • I always chop with a knife on a solid board and don’t use a noisy blender.

Make the toning tea:

  • I use 30g avocado stone with 500 ml water.
  • Water choice is always boiled egg water (i.e., leftover water after boiling eggs) or rainwater. (I have a bucket outside collecting from the roof gutter).
  • I do not add anything to the water at this stage.
  • I bring 500ml to the boil.
  • I add my 30g chopped avocado stone and stir.
  • Lid on and steep for 30 mins
  • A couple of stirs during the steeping
  • Decant the ‘tea’ through a culinary sieve into a measuring cylinder. There is always less than 500mls due to evaporation. I do not top up.

Adding the additive

  • At this stage, I add the additive of choice if I decide to. To date, my choices have been citric acid, Vitamin C powder, and Sodium carbonate/washing soda (0.5g, 1g and 0.2g respectively per 500ml).
  • Note the colour change associated with the additives
  • Stir the mix.


  • Measure pH (not critical but it might be useful – it might indicate that something is different. For instance if you get a different tone than expected this might give you the reason why.
  • The ‘tea’ is likely to still be hot – I wait until the temp is around 50⁰C before adding the print – I note the temperature.
  • I tone for 8 minutes, always face down.
  • I put a cover over the tray to keep the heat in as much as possible.
  • I rarely check the toning ‘progress’ because I don’t find it helpful or representative of the end result.
  • I almost always give the tray a few gentle rocks during the 8 mins.
  • On 8mins I remove the print to a wash of warm water.
  • I aim to take a snapshot of the print before toning (annoyingly I do forget this from time to time), another snapshot immediately upon removal and then over the course of the wash.
  • I leave the print in the wash for a couple of hours minimum and up to 12 hours (occasionally with a water refresh ½ way).
  • I hang it up to dry.
Cyanotype toned using avocado
Figure 2 : x2 cyanotypes pre-toning
Cyanotype toned using avocado
Figure 3: x2 Cyanotypes immediately post toning – note prints still wet and vibrant
Cyanotype toned using avocado
Figure 4: x2 cyanotypes after approx 6 hours in wash bath
Cyanotype toned using avocado
Figure 5 x2 cyanotypes after approx 12 hours in wash bath – note change in tone

Notes on toning cyanotypes using avocado

  • The toned image straight from the toning bath is never the end point colour.
  • I find the ‘curing’ process after removal from the toning bath super exciting as the print often goes through some beautiful stages. For instance, with washing soda, the print taken directly from the toning bath is often a lovely orange and watching this change with time is amazing.
  • Differing the amounts of additive will lead to different toning colouration.
  • I find that these relatively short times in the toning bath only minimally stain the paper (I have not explored shorter toning times to reduce the paper staining further).
  • I have not found a way to stop the toning reaction immediately upon removal from the toning bath. I did attempt to neutralise it but all that did was create alternative colours. I now accept that the colour change associated with the drying or ‘curing’ as I call it, is a function of the toning process.
  • It was in trying to neutralise the primary toning that led me to look at using different additives.
  • I have recently used the above process with oak acorns. And again, the curing process was evident.
  • For me the vitamin C powder had the most unexpected results. Straight from the bath, the print would be a beautiful turquoise but upon curing it transformed to a wonderful powdery grey.


Thanks to Malin for asking me to write this article. This led me to look further into the process and formalise it.

Consumables and equipment

I totally recommend reviewing all the wonderful resources on, and definitely purchasing the books associated with cyanotype and toning.
I think the only curly resource is the UV lighting for the initial cyanotype and as mentioned I recommend the solution offered up by Mat Marrash on Large Format Friday.

Clive Pigott is English and has lived in Wellington, New Zealand since 2006. He has always loved photography, more so after watching the movie ‘Blow-up’. Shoots with Fujifilm, Nikon, Chroma Snapshot and other cameras. Uses digital and film (35mm and 4×5 sheet). Is amazed at the results of using Caffenol as a developer. Enjoys making Gum, Cyanotype and Anthotype prints.

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Get the cyanotype toning book by Annette Golaz
Cyanotype toning: Using Botanicals to Tone Blueprints Naturally book by Annette Golaz

Cyanotype toning: Using Botanicals to Tone Blueprints Naturally

by Annette Golaz

A two-part book with a step-by-step how-to section and artists who have explored toning.
Recommended reading to learn cyanotype toning.


3 thoughts on “Cyanotype Toning with Avocado Stones”

  1. Hey Sandy, thanks for leaving a comment and for appreciating my article. I understand you wrt the ‘overwhelm’ – but that’s the great thing there are just so many options. I started out by heading down to the local Indian spice shop and buying a heaps of things, all relatively cheaply – Moringa leaf smelled absolutely wonderful and that in itself made it all the more enjoyable. My advice (if you don’t mind me saying) to get you started is to get a number of cyanotypes of a single image you like, and then just have a play with various botanicals – following Annette’s guidelines – you’ll be amazed at how addictive it is.

    Anyway, have fun, thanks again and let us know when you’ve got some results :]

    ps I am a bit slack with my Instagram postings – sorry

  2. Thank you for this great article! I have been working with the cyanotype process off and on for over a decade as a hobby and am looking to “up my game.” I have both the books you mentioned and am overwhelmed with the number of options Annette lists in her book. I, too, love the idea of using things that are just going to get thrown away, and the grey toning you show here is beautiful. I’m going to give it a try! I also plan to see if I can find some of your other work on the web somewhere. All the best!

  3. Thank you for this inspiring article. Your detailed description of your toning process is very helpful and the results look more than promising. After reading this I saved my first avocado pit for further processing later in the day.

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