Darkroom Chemicals: Everything You Need to Know

In a darkroom, the chemicals you use and how you use them could make the difference between a good photo and a great one. Shooting on film and developing your own images gives you control and your pictures gain a depth and feel that does not come across on a digital image. When starting out with developing your own film and making prints in the darkroom, you may have questions about the overall process – especially about the chemicals involved. Keep reading to find out all you need to know about the chemicals used in the photographic darkroom.

The Three Chemicals Used in the Darkroom

Today, setting up a darkroom in your home is a possibility and pretty simple. Whether you are developing your own film or just making prints from existing negatives, the process for developing the light-sensitive materials, paper or film, is basically the same. 

Very simply, you need three basic darkroom chemicals:

  • A developer makes the pictures appear
  • A stopbath stops the process
  • The fixer rinses away the excess chemicals and “fixes” the picture in place.

Developer: Starting the Process

A developer reacts with the silver halides, making a picture appear. For black and white film, you use black and white developer. For color film, you need to use a different developer for C-41 chromogenic color print film. C41 is the most common type of color film and contains dyes to bring out the different hues.

Stopbath: Stopping the Process

A developer will keep developing unless you stop it. If you wait too long, your film or print will be over-developed. A stopbath stops the developing process by neutralizing the developer. Because stopbath is acidic, it has a strong vinegar-like smell.

Fixer: Finalizing the Process

Once the stopbath has done its job, you want to stabilize the process. Fixer rinses away any leftover silver halide as well as the other darkroom chemicals so you can safely expose the film or print to light.

Other Darkroom Chemicals

The three basic darkroom chemicals of developer, stopbath, and fixer are fundamentally all the darkroom chemicals you will need to get started developing and processing your own film and prints. However, there are other darkroom chemicals that can simplify the process, make the process more efficient, or enhance the process.

Photo-flo Creates Streak-Free Photos

Photo-flo is a Kodak product used to reduce water spots and streaking when you are developing film. It may not be essential to have in your darkroom chemical collection, but it will help your pictures look their best.

Bleach and Fixer Makes Blix

A bleach and fixer combination, Blix is used to remove the final layer of chemicals on color film. This last chemical rinse finalizes the process and stabilizes the image so after this step it is not sensitive to light.

Monobath Combines The Three Basic Steps Into One

 Monobath (Mono meaning one) is a chemicals that combines all three darkroom chemicals into one. By blending all three into one single liquid, you shorten the time for processing as well as save money. There are two common monobath brands:

Clean up With Photo Emulsion Cleaner

Photo Emulsion Cleaner or PEC cleans up your photos by removing almost anything that has made its way onto them. This could include:

  • Fingerprints
  • Mildew
  • Smoke residue
  • Ink  

Photo Emulsion Cleaner is a darkroom chemical to keep around even if it is not part of the developing process.

C41 Processing Kits Contains What You Need For Color Film

If you are working with color film, you will need a C41 kit. These kits contain developer, bleach, and stabilizer. Some are in liquid form while others come in powders. There are several companies that sell C41 kits:

Black and White Developers 

For black and white processing, some suggested darkroom chemicals for developing are:

  • Kodak D-76 – A powder, this developer is an oldie but goodie. D76 was originally made by Kodak in 1927. This is one of the most popular developers.
  • Ilford ID-11 – This powder developer is essentially the same as the D76 with some minor differences. Both Ilford ID-11 and Kodak D-76 are considered standards for developers.
  • Kodak XTOL – A two powder developer, Kodak XTOL is known for its ability to handle fine grain and provide high sharpness. 
  • Adox Adonal or Rodinal – This liquid has a reputation for fine grain and high sharpness. This is highly concentrated and can only be used once and cannot be reused. Unlike most liquid darkroom chemicals, it has a very long shelf-life.
  • PMK Pyro – PMK stands for Pyro-Metol-Kodalk. Available in liquid form and manufactured by Kodak, it gives you consistent results with high sharpness. Its staining ability gives you a broad tonal scale and that rivals any others. 

There are so many choices in developers, and these are just a few. You may need to sacrifice some film to test while you experiment to discover which are the best darkroom chemicals for your darkroom.

Eco-Friendly & Low Toxicity Darkroom Chemicals

It is possible that you want more eco-friendly and low toxicity options for darkroom chemicals for developing film or but you still want them to be effective. If this is true for you, then I recommend the LegacyPro EcoPro line of darkroom chemicals. There chemicals are:

  • Virtually Odorless
  • free of known carcinogens and mutagens
  • free of Metol, hydroquinone, borates, and phosphates
  • free of non-biodegradable organic compounds: EDTA and DTPA
  • Free of acetic acid, perfume, and dye
  • Designed to minimize chemical wastage
  • Still is Archival
  • Has an extended tray and shelf life
  • The EcoPro fixer can be used with both a water bath or stop bath. However, when used with a water bath the fixing time is cut in half.

LegacyPro EcoPro darkroom chemicals come in formulations for both black and white film and darkroom paper. You can find some of the EcoPro line on amazon.com and but the website freestylephoto.biz has more options to choose from.

What is a Darkroom and Why do People Still Use Them

Digital cameras seem to have taken over analog photography, but old-fashioned film cameras still have their fans. When you develop and handle your own film and photos, you control the process. A darkroom is essential to experience the manual, hands-on method and adds something to the final product that is not always present in a digital picture.

A darkroom is exactly that: a room that is dark. It doesn’t have to be big or fancy. A darkroom is simply a place where all light is blocked. How big or fancy that darkroom is depends on what you have space for and what you want to accomplish.

Both film and photo paper are covered with a thin layer of silver halides suspended in a layer of gelatin, resin, or polyester, depending on which you are using. These silver halides change their chemical structure when exposed to a light source. When exposed to different darkroom chemicals, the silver halides leave an impression on the film or paper producing a picture. 

Photography has been around for over 150 years. The first type of photography used glass plates called Daguerreotypes. These plates were coated with a wet emulsion of silver halides and needed to be processed immediately, making them awkward and hard to manage. A home darkroom at this time was impractical and almost impossible. 

In the twentieth century, George Eastman developed a dry process that could be put onto plastic film and loaded into your camera. As long as the film stayed in the dark of the camera, you could save it to develop it later. This opened up a new world for the amateur photographer.

Still, film is very sensitive to light. Developing film was difficult and the process was time-consuming and difficult. It wasn’t until Kodak started processing film rolls and delivering the negatives, and thus saving a step, that people started to really be interested in working in their own darkrooms to print their own photographs.

Setting Up Your Own Darkroom

Before you start to buy your darkroom chemicals. You will need someplace to work. You only need a few basic things to set up your own darkroom.

What to Look For In a Darkroom

  • A dark space- It is the silver halides on the paper or film that are sensitive to light, not the darkroom chemicals themselves. Because the film is especially sensitive to light; you need a room that is completely dark. It doesn’t have to be a big space, but it does have to be dark. 

Having a space that is completely devoid of any light can be a challenge both to maintain and to work in. To simplify things and to save you from stumbling around in the dark, a changing bag is recommended. 

One way to test that your darkroom is dark enough for making prints is with all of the lights off (even the safelight) to put a fresh sheet of darkroom enlarging paper with the emulsion (or light-sensitive) side up in the middle of the room you want to use a darkroom. Put something on it that covers the paper (for example, your keys, batteries, or think paper). Let it sit for at least an hour in your darkroom with the lights off. After the hour, develop the sheet of paper using the right process depending on your paper type (RC or Fiber-based paper for black and white development or color paper). If you can see the outline of the object or if the paper darkens in any way, then you need to make your darkroom more light-tight.

  • Access to a sink- You will need access to water to rinse the film. Also, some people also dump their used chemicals down the drain. This is not always advised and can be dangerous for sewage treatment systems and the environment. Check your local ordinances for what is allowed.
  • Someplace to store your darkroom chemicals- This may seem like a no-brainer, but it really depends on where you set-up your darkroom. If it is in a closet or similar small area, you may not have a place to put the darkroom chemicals. 

You should avoid storing your chemicals on the ground where they can be kicked over and spilled. Also, having them up high could cause a problem if your darkroom chemicals get jostled and fall off the shelf.

  • A dustless place to hang you developed film or prints while they dry- Little bits of dust on your film may seem unnoticeable to the naked eye, but those dust mites grow into full-fledged dust bunnies under a photo enlarger. Also, you don’t want those little nasty bits all over your final print after you spent so much time and effort getting it perfect.

Equipment You Need to Set Up Your Darkroom

Once you have established where to build your darkroom, you need to make sure you have the right equipment needed to get the work done. Whether you are developing film or prints, you use the same darkroom chemicals. We will go over which chemicals you need and what types later. What changes between developing film and prints is the equipment you need to use for those darkroom chemicals.

Once you get the hang of it, developing film in your own darkroom is not hard. You need to practice opening the film canister and getting the film on to the developer canister reel literally with your eyes closed. Once you have that mastered, the rest is simply timing when to use which darkroom chemical. I recommend practicing with a ruined roll of film with the lights on first, to help you get the hang of the process before doing it with a roll of your images in the dark.

The first thing you need to develop film is a changing bag. A changing bag is a big black bag made of anti-static material with a place to put your arms. There are also changing tents and changing boxes. 

In your changing bag you put:

  • The unopened film roll
  • The developer canister with reel (like this Paterson developing tank)
  • Scissors for trimming the ends of the film
  • Bottle opener for opening the film canister

Other equipment you will need for developing film or prints are:

  • A timer
  • A Safelight (A Red light, red safelight bulb, or red filter)
  • A thermometer
  • Graduted Cylinders for measuring (like these from Amazon.com)
  • Bottles of varying sizes for mixing and storing darkroom chemicals (I prefer to use glass as long as it isn’t in direct sunlight but plastic bottles also work well).
  • Funnels
  • Film clips or clothes pins for holding the developed film straight while it dries to prevent curling.

When you have your film developed, you can move on to the next step, which is printing your photo.

The biggest change in developing a picture and film is that for prints, you don’t need to work in total darkness. Paper is not as sensitive to light. A safelight emits a red light that is off the visible spectrum. The red light does not affect the chemical compounds of silver halides on the paper. (For more information about why darkrooms need to be red, then read my article here).

The other equipment you need to print photos in your home darkroom are:

  • An enlarger
  • Tongs
  • 3-4 Processing trays of different colors (one for each type of chemical)
  • Squeegee

And to keep you neat and clean, these are optional but highly suggested:

  • Apron
  • Googles or glasses (to chemicals from splashing in your eyes)
  • Rubber gloves

Where to Buy Your Darkroom Supplies Online

In the old days when film was more prevalent, you could stop by your local film store for supplies and advice. For most, those days of a local camera shop are gone. Nowadays you can get advice from online forums and order your supplies from Amazon.

Of course, Amazon.com isn’t the only place to obtain your darkroom chemicals. Websites like the following offer both supplies and helpful tips:

Now that we have all the equipment, let’s talk about everything else you need to know about darkroom chemicals.

The Dangers of Darkroom Chemicals FAQ

Most hobbyists consider the chemicals they use to be very safe. And generally speaking, darkroom chemicals when mixed and used properly are not toxic. The problem is that some home darkroom enthusiasts are not trained on the proper use and handling of darkroom chemicals. That could lack of understanding could make the difference between a safe hobby and a dangerous one.

There are always dangers when using any type of chemicals. Always use caution when working with darkroom chemicals. Let’s take a look at some facts about the dangers of darkroom chemicals.

  • The dry, concentrated, form of most darkroom chemicals can cause problems if inhaled.
  • Some people are sensitive to powders and may have breathing problems if they breathe them in while mixing them so be sure to mix them in an area with plenty of ventilation, like outside.
  • Some darkroom chemicals such as toners, release toxic fumes while processing. Always make sure your darkroom is adequately ventilated and you have access to fresh air.
  • Darkroom chemicals are irritants. If you touch them with your bare hands, some darkroom chemicals can cause contact dermatitis or you can build up an allergy to them over time.
  • If you get darkroom chemicals in your eyes, immediately flush with water and get help. Darkroom chemicals are irritants and could become a problem after repeated exposure to your eyes.
  • Darkroom chemicals are not flammable.
  • There is no consistent proof that darkroom chemicals can cause cancer.
  • If you are pregnant, you should always use precautions in anything you do. Working in a darkroom is no exception. Although there does not seem to be any problems with pregnant women working with the chemicals used in a darkroom, if you have any concerns you should check with the manufacturer. 
  • Color darkroom chemicals are more toxic than black and white chemicals for you and the environment so always take precautions like wearing gloves, an apron, protective eyewear, and a mask when using color development chemistry – especially when mixing and using the open tray method of development.

Powder Versus Liquid Darkroom Chemicals

Darkroom chemicals come in either a powder or liquid form. Which is best is open for debate and is really up to you and what you prefer.

Powder darkroom chemicals last longer. However, they need to be mixed in a certain way. At some point you may use hot water while at another time you need to user cooler water. Also, you need to be precise in your measurements to ensure you get the right ratios for the best results. Furthermore, as mentioned, the powder can become airborne and cause issues if you breathe it in or have sensitivities.

Some examples of powder darkroom chemicals are:

Liquid darkroom chemicals are easier to mix but they don’t last as long. As powder darkroom chemicals are not activated, they can last for as long as you have them. Liquid darkroom chemicals can, however, be mixed in smaller batches which means you won’t use as much or waste as much. 

Two very popular and reliable liquid developers are:

While powder darkroom chemicals are fine, it is suggested that beginners start with liquid darkroom chemicals until they are more experienced.

How to Store Darkroom Chemicals

Storing your darkroom chemicals is actually easy. You can use special bottles designed for that purpose. These can be dark glass or opaque plastic. Many photographers use two-liter soda bottles as well and have no problems.

You need to keep as much air out of your darkroom chemicals as possible. This may mean adding a few glass beads to a glass bottle to push out the excess air. 

It is suggested that you use a dark-colored bottle although some debate this. However, you store your darkroom chemicals, make sure they are kept somewhere out of the way. You don’t want them to spill and cause a mess. You also don’t want children to get ahold of them. It is a good idea to clearly label all your darkroom chemicals for safety and your own convenience.

All darkroom chemicals should be kept in cool, but not cold, dry places. Do not keep your chemicals in the fridge. It is also not a good idea to keep them in the damp air of a bathroom.

If stored properly, some darkroom chemicals can last a very long time. Some people have reported stopbath and fixers lasting years, sometimes decades. 

In general:

  • Developers can last up to six months if properly sealed.
  • Stop baths can usually last for years. As long as the color is a straw yellow, you are good to go.
  • Fixers are good for months as long as the pH stays the same. 

For specific details, refer to the manufacturer’s website. Also, most darkroom chemicals come with a data sheet with storage information.

Can You Reuse Darkroom Chemicals?

Some darkroom chemicals can be reused up to a point. It depends on the process you are using, the darkroom chemical, and how much the reused chemical affects your outcome. See the following tips for what chemicals you can reuse, but you should follow the manufacturer’s guidelines on your package for each chemical.

Color Darkroom Chemicals

Most color darkroom chemicals are one-shot, meaning they are meant to be used only once. For example, this Artista RA-4 color print processing kit on bhphotovideo.com is a one-time use product. However, there are other kits for processing color that can be used multiple times like this Tetenal RA-4 Color Paper Processing kit from freestylephoto.biz, which can do up to 200 8×10 prints.

Black And White Chemicals

Depending on whether you are developing film or making prints in the darkroom, whether or you not you can reuse the three chemicals used in the black and white process will change:

Film & Prints Developer

With film developer, you do not want to reuse it since the developer will become exhausted after each use.

However, most developers used to develop prints in the darkroom can be reused as much as needed during a single session by pouring it back into the storage container after each use. Since you can actually see your print develop in the darkroom using a safelight when making a black and white print, you can see when the developer starts to slow down. Keep in mind, each time you reuse it, the strength of the developer weakens and requires a longer amount of time to develop your film or print.

Film & Prints Stop Bath

Stop bath can be reused again for both film and print development by pouring it back into the storage container after each use and can be reused until it has exhausted. If using a color indicator stop bath (like this Kodak Color Indicator Stop Bath from amazon.com) you will know when this happens because the color of the stop bath will change to a purplish-blue color.

Film & Prints Fixer

For both film and print development, you can use fixer again and again until it reaches its expiration by pouring it back into the storage container after each use. Remember though, each time you reuse it, the strength of the fixer weakens and it requires a longer amount of time to fix your film or print.

A good way to check the potency of your fixer is to use hypo-check (find it here on Amazon.com). Before using your fixer, pour some of the solution into a graduated cylinder and add 1 – 2 drops to the fixer. If it does nothing then your fixer is fine to keep using but if it turns a cloudy white, you have an excess of silver halide in your fixer and it should be disposed of properly before mixing a new batch.

How to Dispose of Darkroom Chemicals

Once your darkroom chemicals have reached the end of their life, it is tempting to just flush them down the sink. While darkroom chemicals used in a home darkroom do not impact the environment as much as a larger commercial facility, they can still cause some harm. Pouring them straight down the drain is not just a bad idea because it can be bad for the environment but in some cases, it can be illegal. Disposing of your spent darkroom chemicals in a way that has minimal impact on the environment can be easily managed without too much effort on your part. However, if you have a septic tank see the last paragraph.

Color Darkroom Chemicals

While it is possible to dilute color chemistry to make it safe enough to pour it down the drain, I recommend that you don’t take the chance and avoid pouring them down the drain altogether. Instead, I recommend collecting your color darkroom chemicals by pouring them into a disposable container like an empty milk jug once they are exhausted. After you have collected enough, dispose of them properly by transporting them to the nearest hazardous waste disposal facilities to you. An alternative to disposing of chemicals used in your darkroom is to take them to a photo lab, if you can find one, and ask them to dispose of them.

Black and White Darkroom Chemistry

In black and white darkroom chemistry, the purpose of stop bath is to neutralize the developer. Developer is an alkali and stop bath is an acid. Therefore, if you mix the two chemicals together, the result will be a neutralized solution that can safely be poured down the drain. To make sure all the chemical reaction has been neutralized, follow the mixture with first cold water, then hot water.

For black and white darkroom chemicals that contain silver such as fixers or toners, the silver in it needs to be recovered (or collected) and be delivered to a hazardous waste disposal site. To recover the silver, you can put the used chemical into a bucket with some steel wool. After about a week, the silver should be collected in the pad. You can then carefully pour out the rest followed by cold and then hot water. You can then take the steel wool or steel ball to the nearest disposal site when you are ready.

A note if you have a septic tank. The chemicals used in the darkroom could have a negative effect on the bacteria that live in your tank and keep it healthy (keeping your septic healthy is as easy as using a product like Rid-X once a month). To keep from damaging your septic system, I recommend collecting your darkroom chemicals and pouring them into a disposable container once they are exhausted and not pouring them down the drain. Once you have collected enough, dispose of them properly by transporting them to the nearest hazardous waste disposal facilities to you. An alternative to disposing of chemicals used in your darkroom is to take them to a photo lab, if you can find one, and ask them to dispose of them.

Darkroom Chemicals Safety Tips

Staying safe in the darkroom when you are using chemicals is important if you want to be successful in your hobby. Here are a few tips to keep you safe.

  • Keep the wet and dry chemicals away from each other.
  • Use color-coded trays to keep each chemical separate.
  • You should always wear gloves when developing prints in chemicals.
  • To avoid contact with any darkroom chemicals, you should always use tongs when handling the photo paper.
  • Make sure your darkroom is well-ventilated. This is especially important if you are mixing chemicals.
  • Always add acid to water. 
  • Always add water to the powder.
  • Label your darkroom chemicals.
  • Keep your darkroom neat. Put things back where you found them.
  • Don’t eat, drink, or smoke in the darkroom.
  • Have a spill kit nearby and know how to use it.
  • Use googles, an apron, and gloves to protect yourself when handling and mixing chemicals.
  • Once you have filled the processing trays with chemicals, don’t move them and risk spilling everything. 
  • If you have an accident, don’t hesitate to call for emergency help.
  • Keep your chemicals out of the way and not on the floor when using the darkroom.

Lee

My name is Lee and I love photography and learning. I received a Master of Fine Arts in Photography in 2010 and have worked as a university professor for the last 10 years in addition to being a working photographer. I started this website to learn more about digital and film-based photography and to provide a resource for all of my students.

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