How to Make a Spore Print: A Step-by-Step Guide

A spore print is one of the simplest and most useful things you can make with a mushroom. You need a cap, a piece of paper and a bowl. A few hours later, you have a pattern made of thousands of spores, in a colour that can help narrow down what the mushroom is.

Spore prints are used by foragers checking an identification, by students learning how fungi reproduce, by artists, and by growers who are curious about the mushrooms they raise. This tutorial covers the basic method, how to handle mushrooms that don’t have gills, how to fix and keep a print, and what a spore print can and can’t tell you.

What a spore print is

Mushrooms are the fruiting bodies of fungi, and their job is to release spores. In a gilled mushroom, the spores form on the gills under the cap. The Wytham Woods guide from the University of Oxford explains that as the cap opens and matures, the spores fall from the gills. A single spore is far too small to see. As the North American Mycological Association (NAMA) puts it, “Mushroom spores are very small and can only be seen individually with a microscope.” A spore print simply collects enough of them in one place to make them visible.

Because the spores drop more or less straight down, the British Mycological Society (BMS) notes that the print tends to mirror the pattern of the gills. That’s why a good print looks like a ghost image of the underside of the cap.

What you’ll need

• A fresh, mature mushroom
• A sharp knife or scalpel, to remove the stem cleanly
• White paper or card, and black paper or card (or a sheet of glass, clear plastic or kitchen foil)
• A bowl, glass or cup big enough to cover the cap
• Optional: a few drops of water, or a damp piece of tissue
• Optional: artist’s fixative or hair spray, to fix the finished print

If you don’t know what colour to expect, the BMS suggests using a card that is half black and half white. NAMA and First Nature also mention kitchen foil and glass, which work well because both light and dark spores show up on them.

Step-by-step: making a spore print

1. Choose a good specimen. Pick a mature mushroom whose cap has opened out so the gills are exposed. The Wytham Woods guide says that a mushroom that is too old or too dry may not give a print.
2. Remove the stem. Cut the stem off level with the cap so the gills can sit close to the paper. First Nature recommends a scalpel or very sharp knife if the stem won’t snap cleanly. NAMA describes an alternative: cut a hole in an index card, push the stem through it, and let the cap rest on the card.
3. Place the cap gills-down. Lay it on your paper, foil or glass. The BMS says there is no need to press it down.
4. Add a little moisture. NAMA suggests putting a drop of water on top of the cap to help release the spores. For small mushrooms that dry out quickly, First Nature recommends a piece of wet tissue on top of the cap.
5. Cover it. Put a bowl, cup or glass over the cap. The BMS explains that this stops the mushroom drying out and reduces the air currents that would scatter the spores.
6. Wait. Leave it undisturbed. Guidance varies, which reflects how different mushrooms behave (see the table below).
7. Lift carefully. Remove the cover, then lift the cap straight up so you don’t smudge the print.

How long to wait

Source	Suggested time
First Nature	Two or three hours
British Mycological Society	At least 2 hours for fresh-picked mushrooms. Overnight or longer for shop-bought ones
NAMA	2 to 24 hours, depending on humidity and how fresh the mushroom is
UF/IFAS Extension and Science Learning Hub	About a day, or overnight

In practice, start checking after a couple of hours. If nothing shows, put the cover back and leave it overnight.

Mushrooms without gills

Not every fungus has gills, but many can still be printed. NAMA and First Nature describe how to handle the main groups:

Type of fungus	How to print it	What the print looks like
Boletes and other pored mushrooms	The same as gilled mushrooms, pores facing down	Dots or rings that reflect the size and shape of the pores
Tooth fungi (spines under the cap)	The same as gilled mushrooms	A dotted pattern
Hard bracket fungi (polypores)	NAMA suggests wrapping them overnight in wet paper towels or newspaper first, then printing with the spore surface facing down	Varies by species
Cup fungi, such as Peziza	Fertile side down	A plain disc with no gill pattern
Flask fungi, such as Daldinia	Spores are released around the fruit body, so make the print beside it rather than under it	A deposit next to the specimen

For morels, corals, puffballs and bird’s nest fungi, NAMA says to experiment or check a mushroom book for where the spores are produced.

Fixing and keeping your print

A spore print is fragile powder and smudges easily. Both the BMS and NAMA suggest fixing it with hair spray or artist’s fixative. First Nature prefers artist’s clear varnish and says hair lacquer is a weaker option. Spray from a distance. NAMA warns: “Hold the spray at least 12 to 15 inches above the print or you may blast the spores right off the paper!”

If you’re collecting in the field, NAMA suggests wrapping the cap, or the whole mushroom, in foil to carry it home, and then making the print there.

Reading the colour

Spore colour is the main reason foragers make prints. NAMA notes that spore colour “can range from white to many other shades, including black”. It groups prints loosely into white, black, and brown or cinnamon. First Nature gives examples at family level:

• Amanitaceae (the family that includes the death cap): whitish spores
• Cortinariaceae (webcaps): rust-brown spores
• Entolomataceae: pinkish spores
• Russulaceae (brittlegills and milkcaps): whitish to yellow or ochre, depending on the genus

A practical tip from UF/IFAS Extension: if no print appears on white paper, the spores may be white, so try a darker colour.

How spore colour helps and where it stops

Spore colour is a strong clue, but only one clue. Wild Food UK’s guide to velvet shank, for example, notes that it has an off-white spore print, while look-alikes such as the common rustgill have rust-coloured spores. That kind of difference can help separate species. But many mushrooms share the same spore colour, including some deadly ones. The death cap, for example, belongs to a family with whitish spores, just like many edible mushrooms. Our death cap guide explains why that matters.

So treat a spore print as one part of the evidence, alongside the cap, gills, stem, smell, habitat and season. Never decide that a wild mushroom is safe to eat based on a spore print, a photo or a description. If you plan to eat something you’ve found, have it checked in person by an experienced local identifier. Our article on wild versus cultivated mushrooms covers the wider safety picture.

Safety and hygiene

• Wash your hands. UF/IFAS Extension reminds readers to wash their hands each time they handle mushrooms. That matters most with unknown wild species.
• Keep prints away from food. Use a dedicated surface and don’t print an unknown mushroom on a kitchen plate.
• Label everything. Write the date, where the mushroom was found and what you think it is next to each print.
• Don’t taste to test. Making a spore print never requires eating or tasting the mushroom.

Going further

Try a shop-bought mushroom first

If you’re new to this, practise on mushrooms from the supermarket. The BMS suggests leaving shop-bought mushrooms overnight or longer. Mature brown mushrooms with open caps are a good choice, and our guide to growing button mushrooms explains how that species develops. The Wytham Woods guide also suggests trying oyster mushrooms. Our oyster mushroom guide has more on that species.

Look closer

To see individual spores, the BMS suggests letting them drop onto a glass microscope slide. NAMA describes scraping a little of the print onto a slide with a needle or scalpel, adding a drop of water and covering it with a cover slip. You’ll need a microscope to see much detail.

Make art

NAMA describes artistic prints made on coloured card, with the cover left off so that air currents shape the pattern. It suggests using them for greeting cards. It also describes an old trick with ink caps: leave them overnight, then mix the black spore deposit with a few drops of water to make ink.

Growing from spores

Some growers start cultures from spores. This needs clean technique, because spores and contaminants land on the same surfaces. If you’re interested, our guide to agar and liquid culture is the next step.

Troubleshooting

• No print at all: the mushroom may be too young, too old or too dry, or the spores may be the same colour as the paper. Try a darker or lighter background, add a drop of water, and give it more time.
• Patchy or faint print: the gills may not be sitting close enough to the paper. Trim the stem flatter.
• Smudged print: lift the cap straight up, and fix the print before handling it.
• Print scattered or blurred: air movement disturbed the spores. Keep the cover on and leave it somewhere still.

Sources and further reading

• Gardner, C. (2024). How to Make a Mushroom Spore Print. UF/IFAS Extension Orange County
• British Mycological Society (2024). How to Make a Spore Print
• Sheine, S. and Rogers, M. How to Make a Spore Print. North American Mycological Association
• First Nature: How to Make a Spore Print
• Science Learning Hub (New Zealand): Making a mushroom spore print
• Wytham Woods, University of Oxford: How to make a spore print
• Wild Food UK: Velvet Shank (Flammulina velutipes)

Featured image: oyster mushroom by Charles Joynson via iNaturalist (CC0 1.0). Inline photo by Rosie via iNaturalist (CC0 1.0).