Cyanotype Tutorial: How to Make Botanical Sun Prints at Home

Cyanotype printing is an early photographic printing process that uses UV light to create beautiful deep blue prints, also known as sun prints or blueprint prints. Every print turns out slightly different depending on the sunlight, the materials you use, and the exposure time.

How Does the Cyanotype Process Work?

The process works by coating paper with light-sensitive cyanotype chemicals. Once dry, the coated surface reacts to UV light. Objects placed on the paper block part of the light, creating silhouettes during exposure. Afterward, the print is rinsed to wash away unused chemicals, and the exposed areas oxidize into the characteristic deep Prussian blue.

Cover your table with newspaper, scrap paper, cardboard, or a plastic sheet before you begin. We also recommend putting on gloves before coating your paper.

These bottles contain the cyanotype chemicals in powder form. Always add water to the powder, not the other way around. Fill both bottles to the marked line, close tightly, and shake well until fully dissolved.

If, after several months of storage, you notice a small amount of mold in Bottle B, that’s not a sign it’s ruined, just strain it through a coffee filter and keep using it.

Once Bottle A and Bottle B are combined, the solution becomes UV-sensitive. The good news: you do not need a darkroom, normal indoor lighting is fine. Simply close the curtains and work under electric room light while preparing and coating your paper.

Mix equal parts Bottle A and B, we start with 10 ml of each, usually enough for 10 to 15 sheets of paper. Once mixed, the emulsion is immediately UV-sensitive, so only mix what you’ll use right away.

Don’t worry if your mixed emulsion looks a little different batch to batch, sometimes more blue-green, sometimes more yellow, that’s completely normal and has no effect on your finished prints.

Use the foam brush to apply a thin, even layer. For a more intense, saturated blue, apply a second coat once the first has fully dried.

Once coated, let the paper dry completely away from light. Avoid stacking sheets before they’re fully dry, residual moisture can transfer emulsion onto the back of the sheet next to it.

Thin leaves, delicate flowers, grasses, and ferns press closely against the paper. Ferns and grasses give fine detail; sweet pea gives curved stems and tendrils; poppies give transparent petals, though they’re fragile; dried flowers hold up well when fresh ones are out of season.

Judge a plant by its shape, not its color, cyanotype only reads contrast between light and dark. If a stem has been sitting in water, dry it off first, droplets leave visible stains on your finished cyanotype.

Arrange your plants on the coated paper, then place the glass frame on top. Clothespins along the edges keep the glass secure.

Place your frame in direct sunlight. Exposure time varies with season, time of day, and cloud cover, treat any number as a starting point, not a rule. Start with five minutes and adjust from there.

Rinse in a tray of clean water or under a gentle stream, avoiding forceful pressure. Keep rinsing until the water runs clear, if it’s still yellow when you lift the print out, it needs more time.

Cover your table with newspaper, scrap paper, cardboard, or a plastic sheet before you begin. We also recommend putting on gloves before coating your paper.

These bottles contain the cyanotype chemicals in powder form. Always add water to the powder, not the other way around. Fill both bottles to the marked line, close tightly, and shake well until fully dissolved.

If, after several months of storage, you notice a small amount of mold in Bottle B, that’s not a sign it’s ruined, just strain it through a coffee filter and keep using it.

Once Bottle A and Bottle B are combined, the solution becomes UV-sensitive. The good news: you do not need a darkroom, normal indoor lighting is fine. Simply close the curtains and work under electric room light while preparing and coating your paper.

Mix equal parts Bottle A and B, we start with 10 ml of each, usually enough for 10 to 15 sheets of paper. Once mixed, the emulsion is immediately UV-sensitive, so only mix what you’ll use right away.

Don’t worry if your mixed emulsion looks a little different batch to batch, sometimes more blue-green, sometimes more yellow, that’s completely normal and has no effect on your finished prints.

Use the foam brush to apply a thin, even layer. For a more intense, saturated blue, apply a second coat once the first has fully dried.

Once coated, let the paper dry completely away from light. Avoid stacking sheets before they’re fully dry, residual moisture can transfer emulsion onto the back of the sheet next to it.

Thin leaves, delicate flowers, grasses, and ferns press closely against the paper. Ferns and grasses give fine detail; sweet pea gives curved stems and tendrils; poppies give transparent petals, though they’re fragile; dried flowers hold up well when fresh ones are out of season.

Judge a plant by its shape, not its color, cyanotype only reads contrast between light and dark. If a stem has been sitting in water, dry it off first, droplets leave visible stains on your finished cyanotype.

Arrange your plants on the coated paper, then place the glass frame on top. Clothespins along the edges keep the glass secure.

Place your frame in direct sunlight. Exposure time varies with season, time of day, and cloud cover, treat any number as a starting point, not a rule. Start with five minutes and adjust from there.

Rinse in a tray of clean water or under a gentle stream, avoiding forceful pressure. Keep rinsing until the water runs clear, if it’s still yellow when you lift the print out, it needs more time.

The provided foam brush contains no metal, which matters, metal-containing brushes (including metal crimps where the bristles meet the handle) can react with the solution.

There’s no single right exposure time, it depends on your light source, paper, and how dense your negative or objects are. In the video, we expose the same flower at three different durations side by side and compare the results to decide which looks best, that side-by-side comparison is much easier to see than to describe, watch this part of the video for the full demonstration.

Start with a small coated piece of paper and a flower on top, just like a normal print. Then use opaque cardboard to cover part of it during exposure:

1. Cover two-thirds of the print and expose for 5 minutes
2. Cover one-third and expose for another 5 minutes
3. Expose the whole print for a last 5 minutes

This gives bands of 5, 10, and 15 minutes total exposure to compare after rinsing. Download our printable test strip PDF to make the same test strip shown in the video, or generate one automatically with our free Cyanotype Negative Maker.

Thin petals let UV through unevenly, creating soft gradients. Poppies and sweet peas work especially well. Underexposed loses subtle detail, overexposed loses the delicate gradients, watch the video to see the difference side by side.

Dry flowers in a flower press or heavy book. Very delicate flowers like poppies can be fragile fresh, sandwich them between two overhead transparency sheets, securing the edges with tape.

Fresh dandelion stems release a milky sap that can stain your paper. Place them between two transparent plastic sheets first.

Place multiple plants on top of each other for overlapping detail, or try multiple exposures: place your first layer, expose a few minutes, remove some plants, add new elements, continue exposing. How long you leave an element in place controls how visible its ghost layer is.

Printed or hand-cut graphic shapes work the same way as plants, anything opaque blocks UV and stays white.

Lace’s open, irregular weave creates intricate patterns, playing with how much UV passes through the gaps.

Feathers

Fine, semi-translucent barbs catch light unevenly, producing soft, textured prints.

Handwriting

Write on a transparency sheet with an opaque marker, then expose it like a negative.

The provided foam brush contains no metal, which matters, metal-containing brushes (including metal crimps where the bristles meet the handle) can react with the solution.

There’s no single right exposure time, it depends on your light source, paper, and how dense your negative or objects are. In the video, we expose the same flower at three different durations side by side and compare the results to decide which looks best, that side-by-side comparison is much easier to see than to describe, watch this part of the video for the full demonstration.

Start with a small coated piece of paper and a flower on top, just like a normal print. Then use opaque cardboard to cover part of it during exposure:

1. Cover two-thirds of the print and expose for 5 minutes
2. Cover one-third and expose for another 5 minutes
3. Expose the whole print for a last 5 minutes

This gives bands of 5, 10, and 15 minutes total exposure to compare after rinsing. Download our printable test strip PDF to make the same test strip shown in the video, or generate one automatically with our free Cyanotype Negative Maker.

Thin petals let UV through unevenly, creating soft gradients. Poppies and sweet peas work especially well. Underexposed loses subtle detail, overexposed loses the delicate gradients, watch the video to see the difference side by side.

Dry flowers in a flower press or heavy book. Very delicate flowers like poppies can be fragile fresh, sandwich them between two overhead transparency sheets, securing the edges with tape.

Fresh dandelion stems release a milky sap that can stain your paper. Place them between two transparent plastic sheets first.

Place multiple plants on top of each other for overlapping detail, or try multiple exposures: place your first layer, expose a few minutes, remove some plants, add new elements, continue exposing. How long you leave an element in place controls how visible its ghost layer is.

Printed or hand-cut graphic shapes work the same way as plants, anything opaque blocks UV and stays white.

Lace’s open, irregular weave creates intricate patterns, playing with how much UV passes through the gaps.

Feathers

Fine, semi-translucent barbs catch light unevenly, producing soft, textured prints.

Handwriting

Write on a transparency sheet with an opaque marker, then expose it like a negative.

Combine a printed negative with real plants or cut templates in the same exposure, for silhouettes, layered compositions, and strong contrast between sharp and organic elements.

Thin plastic bags create soft textures and gradients, wrinkled plastic creates organic waves, layered plastic creates darker and lighter areas, transparent packaging creates geometric shapes.

UV lamps let you work indoors, in winter, or at night, with consistent results. You can even place a small UV nail lamp inside a cardboard box to prop it up and spread light over a larger area.

Besides watercolor paper: colored paper, leftover packaging, tea boxes, book pages, cotton, silk, wool, viscose, and paper towels.

Coat your paper, don’t let it dry, place objects on the wet surface, add ingredients, expose while wet. Try soap bubbles, turmeric powder, vinegar, or salt.

Soak fully dried prints in tannin-rich liquids, black tea, green tea, coffee, or red wine, to shift the blue. To tone: fully expose, rinse, and dry; bleach briefly in 1–2 teaspoons of washing soda per liter of warm water; rinse; soak in your tea/coffee/wine bath starting around 30 minutes; rinse again and dry.

Anthotypes use light-sensitive pigments from plants instead of iron chemistry. See our turmeric anthotype tutorial.

Besides watercolor paper: colored paper, leftover packaging, tea boxes, book pages, cotton, silk, wool, viscose, and paper towels.

Coat your paper, don’t let it dry, place objects on the wet surface, add ingredients, expose while wet. Try soap bubbles, turmeric powder, vinegar, or salt.

Soak fully dried prints in tannin-rich liquids, black tea, green tea, coffee, or red wine, to shift the blue. To tone: fully expose, rinse, and dry; bleach briefly in 1–2 teaspoons of washing soda per liter of warm water; rinse; soak in your tea/coffee/wine bath starting around 30 minutes; rinse again and dry.

Anthotypes use light-sensitive pigments from plants instead of iron chemistry. See our turmeric anthotype tutorial.

Shells

Prime with beaten egg white, let dry, coat with emulsion, place plants while wet, wrap in plastic, expose, rinse gently.

Pebbles

Same egg white primer process as shells. Over-rinsing or scrubbing can lift the layer along with the print.

Fabric absorbs emulsion differently than paper. Cotton, linen, silk, wool, and viscose work best. For garments, slide cardboard inside first to keep the fabric flat.

Ready to Start Creating?

From beginner prints to advanced botanical sun printing, cyanotype is a beautiful way to experiment with sunlight, plants, and creativity.