slime
Slime Recipes (inedible)

Welcome to the fascinating world of non-Newtonian fluids! These slimes, oozes, globs and the rest all have a high viscosity, which means that they have a resistance to flow dependent on the velocity of flow and a proportionate resistance to shearing forces. If something acts on them with a small amount of force (if you stir them slowly, or let you fingers slowly sink into them) they won't offer as much resistance as they would if a greater force acted on them. If you punch a good stout ooze, it should resist about as much as a brick wall. They fight back. Non-Newtonian fluids are so called because they do not fit into one or another of Newton's laws of how true liquids behave (specifically, in how they react to shearing forces). Quicksand, many pastes and glues, gelatin, and ketchup are all Non-Newtonian fluids.

**Elmer's Slime
One of the simplest of the slimes, and a favorite among schoolteachers. Not terribly toxic, but watch the kiddies so they don't eat it. It produces a lovely, white (unless you color it), opaque goo. It will dry out, so store it sealed and refrigerated (zip lock bags work well). It also has a limited shelf life, and may eventually develop mold (horrors!) It (usually) cleans up easily. If it dries on anything, try soaking in water. It is best not to set it on wood, fabric, or any other surface that does not clean up easily.


This is the quick and easy method.
Materials


Teaspoon (or metric measure)
Big jar or measuring cup (1 qt. or 1l)
Bowl - 2 quart (2l)
Measuring cup
Borax powder
4 ounce (120 ml) bottle of white glue (not school glue!)
Water (pref. distilled)
Food coloring (opt.)
Pour the glue into the jar. Fill the empty glue bottle with water, and add to the jar. Stir. You can add food coloring here if you want to be festive - a few drops will do. Pour one cup (240 ml) of distilled water into the bowl and add 1 teaspoon (5ml) of borax powder. Muddle well. Slowly add the glue mixture to the bowl, stirring as you do so. Place the thick slime that forms into your hand and knead until it feels dry. (There will be an excess of water remaining in the bowl.) It will be wet, stringy and messy at first, but the more you play with it, the better it mixes and the less sticky and firmer it becomes. Store your slime in a zip-lock in the fridge. That's it!

Artisan methods: design your slime
The thing that makes this particular slime work is the bonding of polyvinylacetate (PVAC) molecules by the Borax (sodium tetraborate). The molecules (polymers) are long to begin with, and they are tangled, which is why the glue is so viscous. Once the Borax links up some of the molecules, it becomes even more viscous. Not all of the molecules hook up, though. The more that do, the more viscous it becomes, until it reaches a point where it barely flows at all. The amount of attachment that occurs among the PVAC molecules depends in part on the concentration of Borax solution used. This is where we get the latitude for making different consistencies of slime.
All of these variations use the same simple ingredients: a solution of Elmer's glue, and a solution of Borax. The only variations are in the solution concentrations, and in the ratios that the solutions are mixed together.

Most basic recipes suggest a 4% Borax (in distilled water) solution for an average slime. This would be app. 1 teaspoon to half a cup (you've got it easy if you use metric!)

The glue to water ratio is almost always 1:1, though I have encountered 1:.75. This really won't effect the viscosity, however, the amount of water that the slime retains does effect its "stickiness".

The typical glue to Borax solution ratio is 1:1. Ratios of 2:1 and 3:1 are often cited. I have seen them as high as 7:1, but usually the Borax solution was more concentrated. If you want to experiment with making different consistencies of slime, I would suggest two things. First, measure everything metrically, if possible. This makes it much simpler to keep track of concentrations and ratios. Second, start with basic solutions of 50% glue and 4% Borax, mixing them 1:1.

Experiment with increasing and decreasing the concentration of Borax solution, all else being the same. The more concentrated the Borax, the more viscous the outcome. You can actually produce something like a hard rubber ball if the concentration is correct. The lower the concentration, and the closer you approach a wet, sticky liquid. Keep notes so you can repeat the results that you like. If you can't quite get the consistency you want, vary the amount of water that goes into the mix.


**Boric acid and borax method
This formula uses both boric acid and borax to produce a slime that seems drier and stiffer. Mix a solution of 100ml water (preferably distilled), 10ml rubbing alcohol, and 1 to 2ml boric acid powder. Mix well 20 - 30ml of this solution with approximately 50ml of white glue. Make a borax solution of 1 - 2ml borax to 100ml water. Add the borax solution a teaspoon or so at a time to the glue mixture. Stir continuously, adding borax solution until the desired consistency is reached. As with the other white glue slimes, kneading will make the slime drier and more viscous. If the slime feels too wet or sticky after kneading, knead in a little more of the borax solution.

**Gel type glues
Over the past few years several brands of gel type glues have been introduced. Most of these make excellent slimes, and are able to be stretched into large, clear membranes. These slimes can be made to be very elastic and have a nice color and consistency. I have personally experimented with Elmer's School Glue Gel, but there are several similar products available from other manufacturers. Use the quick and easy method or the boric acid and borax method, above. If they are a little sticky when they are stored, they will tend to be stickier after a while. If this happens, see the following paragraph.

Slime overly sticky or runny?
If your white glue or gel glue based slime is too sticky or thin (runny), first try kneading it for a while. Working it in your hands will help to mix things up better, as well as remove some of the moisture. If it is still not quite right, mix 1 part borax with 10 parts water. Dunk the slime into this solution, remove and knead. The more you do this, the more "stout" the slime becomes.

**PVA Slime
This is often referred to as "institutional" or "commercial" slime. This is the type that is generally found in toy stores. It is a little trickier to make, not quite as safe, and more difficult to get the main ingredient for (polyvinyl alcohol) than is the Elmer's slime. But it produces a superior slime. Longer lasting, more transparent, and with a visual and tactile appeal that is more, well, "slimy".
Assuming you can get hold of PVA, it is a fairly simple process to make slime. First, mix a 4% solution of PVA and water. 4 % would be 40 grams of PVA to 9