Messy Materials

There are many materials other than those listed on the main Gunge and Slime pages that can be used for your messy activities and sensory play if you don't want to use gunge. Most will be fairly obvious, but this page will give you some helpful hints and tips.

Safety Consideration
It is essential to remember that whenever you involve anyone else in messy activities, you have a duty of care to them. If you are in business (e.g a photographer), or dealing with members of public (such as a fundraising event), you may be required specifically by law to protect others. Health and safety legislation, for example, will require exposure to hazardous substances to be eliminated.

On this page, I give known examples where the risks to the user are typically low, however, I strongly recommend that you check details of the actual material itself, particularly any warnings on the packaging or associated Safety Data Sheet (SDS) before you use them. It is possible that the hazard might not be immediately obvious, (such as causing dermatitis), so all hazards should be given due attention.

Foodstuffs, toys and cosmetics are generally a good place to start to find suitable materials, but might not be totally free of risks. DIY materials such as paints, glues, sealants, oil & grease, plaster and cement all come with hazards, and should never be used.

Whilst a material may not be inherently hazardous, they may degraded or be contaminated and you should take appropriate precautions to prevent this. Some examples include:
Care over cleanliness in preparation to avoid contamination- especially if preparing away from a kitchen
Use of in date materials and not using 'waste' foodstuffs to avoid degrading or rotting materials
Use quickly after mixing to avoid spoiling, particularly important for materials usually refrigerated for storage

On this site we generally consider materials suitable for skin contact. In most cases food-stuffs could be considered for ingestion if prepared and stored in a suitable manner, but other materials should never be considered as suitable for internal contact. Likewise, no materials can be considered safe for deliberate eye contact.

It is important to make sure that after contact with messy materials, participants are able to wash thoroughly.

Jelly/ Jello/ Gelatine/ Gelatin
Readily available as a dessert and easy to mix, the packaged Jellies have a number of possible uses. The downsides are relatively high cost per volume, need to refrigerate and use cold to stop melting and that it is an animal product.

There are commercial gelatines that will remain stable outside the refrigerator once set if mixed in sufficient quantities (I have used 10%). These are sometimes known as 'ballistics gel'- infamous on Mythbusters or "prosthetic gelatine". They can be obtained from commercial food ingredient suppliers. The setting power is measured in 'bloom', typically for 'ballistics gel' the 300 Bloom grade is used, but standard cooks gelatine is less.

Vegetarian jelly is different type of thickener and will therefore behave in similar ways to the materials introduced on the main slime page.

Widely available, and can be quite cheap, its other main advantage is that it is very easy to wash off, probably the best messy substance in this regard.
Some foams can cause a slight skin reaction to some people so there is an advantage to those sold for people with sensitive skin if felt necessary. If making 'custard pies' it is also best to allow it to stand for a little while before use to allow evaporation of any excess propellant.

Standing the cans in hot water for 10 minutes before use will improve the quantity of foam. If this is done, a typical 250ml can (in the UK) will produce 3-4 litres of foam.

The nozzles on shaving foam cans will usually work in filling balloons with a bit of care. It is also possible to modify the nozzle to allow it spray a distance. One method that I have done that works well is to swap the nozzle for one from a spray paint can, and to carefully drill out the nozzle with a 1mm drill bit. This will enable an effective spray of around 2m.

Whilst a little awkward to mix, it is possible to colour shaving foam with food colouring. Small quantities of water mixed in will make the foam more pourable.

Cream
An obvious example and key ingredient in many a slapstick skit; effective and edible, its main downsides are how quickly some canned whipped creams collapse; you may need to experiment to find a favourite. It is also worth bearing in mind that in common with most dairy products they will also quickly spoil if not refrigerated and leave lingering smells.

Savoury Sauces- Ketchup/ Mustard/ BBQ etc.
I recommend avoiding unless a specific need calls for them. These can be acidic or astringent, so are best avoided. Suitable substitutes can usually be mixed up from gunge.

Sweet Sauces & Syrups- Chocolate Syrup/ Nutella/ Ice Cream Topping/ Treacle etc.
Most sweet sauces will work very well and will likely be the most widely accepted as a pleasant type of mess. Downsides are mainly cost, but due to the level of sugar some (treacle particularly) can be very sticky and hence difficult to wash off. It is also worth bearing mind they can attract insects when used outside.

There are quite a range of types of syrups, but all have one thing in common- they are primarily based on a sugar. The most common sugars encountered are Sucrose- common table sugar, Fructose and Glucose. The syrup also contains water, and usually a range of other components in much smaller quantities- these alter flavour and colour primarily, but can include various vitamins and minerals too.

Geographically the different types of syrup have different availability- for instance corn syrup is uncommon in the Europe, and in the UK we use molasses derived from sugar beet which differs in flavours to that derived from sugar cane.

The rheology of all the syrups tends to be similar; they are all approximately Newtonian which means they differ from most commercial thickeners and therefore have a different visual effect.

Cake Decorating Ingredients- Icing/ Frosting/ Sprinkles/ Marshmallow Fluff etc.
Similarly to the sweet sauces these can work very well. Some have a tendency to melt somewhat when hot as will occur if used on skin, therefore if mixing from scratch the proportions need to be controlled for what you intend to do with it. The cheapest option is to mix a basic water icing with just icing sugar, water and any colouring you need but this can take time for any significant quantity.

Marshmallow fluff/ marshmallow cream are a sticky, but effective ready-mixed mess if budget isn't particularly important.

Mash - Smash/ Instant Potato Mash
Instant mashed potatoes will hydrate fairly effectively if mixed with cold water and allowed to stand, although using boiling water will result in a higher viscosity for the same amount of water. The texture of mash is quite different to many other types of goo which may be an advantage.
Mash was beloved of Bodger and Badger- as "everybody knows, badgers love mashed potato".

Cereals - Oats/ Weetabix/ Cornflakes etc.
Oats are one of my favourite alternative messy substances. They are relatively cheap and widely available, and need little prep. They are available in range of types, but at the very least need to be rolled which if bought as porridge oats they inevitably will be. Preparation is simply by mixing with water in a suitable quantity and allowing to stand (although you can of course make porridge with hot water). If using cold wtities are 1 part oats to 2.5 parts water by mass, giving you approx. 3.5 parts by water volume, but this will depend slightly on the type used. ater, you will need to leave it to hydrate for at least 12 hours for the best goo. Typical quan
Oats don't take food colouring well- you need an awful lot to get a strong colour.
Oats can dry out very hard and be difficult to clean off as anyone who has left a cereal bowl out will attest, so best to wash down whilst still wet.

Other cereals will hydrate in water to a range of different types of mush. The texture of these can vary widely, which is an advantage and they can lend this texture if mixed with other types of gunge. Like oats, simply mixing with water and allowing to stand works well.

Custard Pies- Coolwhip, Dream Whip & Cream Substitutes
Coolwhip is an artificial substitute for whipped cream which is widely used for 'custard' pies in the USA. It isn't readily available elsewhere in the world, although similar products are. Dream Whip is an equivalent available in the UK, although not in all supermarkets, and commercial baking suppliers carry similar products that would be an appropriate alternative. Key advantages over whipped cream are stability- they do not readily collapse as real (or canned) whipped cream is apt to do. They will also survive without refrigeration, and are therefore a good solution for 'custard pies'.
Normally these cream substitutes are mixed with milk and whisked, but they work equally effectively when made up with water, although mixing can take a while and so a food processor is recommended.

The base of a custard pie is an important part of the visual effect, and so if this is important to you the best options are pre-made edible pie or flan cases. These will however be somewhat fragile for handling and can be relatively expensive, especially if many are needed.

Paper plates or aluminium pie tins are an obvious cheap base alternative, but provide no padding underneath and have the potential to have sharp edges, so care needs to be taken. For these reasons I prefer to use a foam base- a circle cut from upholstery foam around 10" diameter and 1/2" or more thick. Some circuses use such a technique, but with more sculpted shapes (A).

Other possible options are to use a meringue mix- some of the commercial custard pie products sold as a powder are based on a dried egg mix like this. It is also possible to buy commercial custard pie foam in a can, manufactured by Smiffys which can be effective for small quantities, but will get expensive for larger quantities. It is of course also possible to use shaving foam as described above.

Flour/ Dough
Flour would at first glance appear to make a good messy material, but when wet it becomes a good adhesive and becomes difficult to wash out, particularly from hair. Having said that, in the right sort of environment it can be a very effective mess.
There are many types of playdough recipe around, so at present I am not going to publish any on this page. Those that contain cooking oils however has less tendency to become sticky and are therefore easier to wash out.

Cornflour/ Cornstarch/ Ooblek
Cornflour (UK) or Cornstarch (US) is a starch based flour often used as a thickening agent in cooking in such items as stews, gravy etc, and is the base ingredient in custard (pudding).

The powder is less 'sticky' than wheat flour and so is a better option for activities that need a messy powder, and indeed forms the basis of some of the colour/ Holi/ Gulal/ Throwing powders available (A). The powder can be coloured by mixing a small amount of water with food colouring, mixing with the powder and then drying- either in a low oven or in the sun.

When mixed with water, the cornflour has slightly unusual properties- it is a 'non-Newtonian' fluid- one where how it flows depends on the force applied to it. This means that when pushed hard or hit, it appears almost solid, but can be allowed to flow like a liquid when released. It has popularly become known as Ooblek after the Dr Seuss book 'Bartholemew and the Ooblek'.

You may have seen one of the demonstrations on kids TV and popular science programmes such as Blue Peter or Brainiac (B) of 'Walking on Custard'- these are large scale demonstrations of the effect where it is possible to walk on the mix as long as you keep moving.

Cake Batter
Cake batter slime is very popular in the US as a simple slime to make at home; take a packet and mix up with some added food colouring. The additional ingredients over flour make it a simpler option to wash off, and it is widely available in groceries. It is less commonly available in the UK and elsewhere.
Cake batter slime is a favourite of many of the videos found on YouTube due to it's simplicity

Paint
There are obviously many types of paint available that have potential as messy supplies; however I would recommend that you restrict your use to paints intended for kids use. Some of the ingredients in household and other paints can be quite hazardous.

Powder Paint
When mixed with water, powder paints form a relatively low viscosity of paint. They are cheap if bought in bulk and can be readily used to colour water. They can be used dry as a powder- many of the colour run, Holi celebrations etc. that have become common in the last couple of years use this as a base. These paints have fallen out of popularity in recent years, and so can be difficult to find on the high street but can still be bought from educational suppliers.

Ready-mixed paint/ Tempera/ Poster Paint
There are a number of types of paint sold as ready mixed, but most of them can be used in messy activities. If quantities larger than a bottle full are needed, bulk packs (typically 5 litres) can be purchased from educational suppliers. If even larger quantities are needed, as paint parties are tending to use, then a thin gunge can be made with a higher degree of powder paint than normal (8% is typical). This will give the visual effect of paint.