Slime School

How to keep a tub of Compound Kings slime soft for months

A tub of Compound Kings slime does not wear out from use. It dries out from being left open. Here is how we keep ours alive on the shelf, and what brings a stiff rim back.

A row of scented slime tubs with lids pressed down

What actually dries a tub out

Moisture leaves our compound through the open surface, and nowhere else. A tub with its lid down loses almost nothing over months. A tub left open on a table overnight loses enough from the top two millimetres that a crust forms, and once that crust gets folded into the body, the whole tub turns grainy.

A tub of blue raspberry slime with the lid resting beside it

The second cause is heat. Warmth speeds the loss, so a windowsill in summer or a shelf above a radiator will stiffen a tub in days rather than months. Cold is harmless — a cool cupboard is the best place a tub can live.

Press the lid fully down after every session
Keep tubs out of direct sun
Keep tubs off radiators and away from heat vents
A cool cupboard beats a warm shelf every time

Reviving a rim that has gone stiff

A dry rim is recoverable and a dry tub is not. If the edges have hardened but the middle is still soft, lift the stiff ring out, break it up, and knead it back through the soft compound. It takes a few minutes and the result is slightly firmer than the original, which most people prefer.

A large bucket of fluffy butter compound opened on a table

What does not work is adding water, lotion or fresh activator. Water sits on the surface and makes the outside slippery while the inside stays hard; lotion turns the body greasy and permanently loose. If the whole tub has set, it has reached the end.

Break the hard rim up before kneading it in
Give it five minutes of working before judging
Do not add water, lotion or activator
A fully set tub is finished — do not try to rescue it

Storing a multipack between events

Sealed mini tubs are the easiest thing in our range to store, because each one is its own container. A box opened for a birthday in March can sit in a cupboard until a class party in June and the unopened tubs will be exactly as they were.

A forty-eight count box of sealed mini slime tubs

Keep the outer box rather than loose tubs — not because the tubs need it, but because loose tubs end up at the back of a drawer with a lid half on. The box is the thing that keeps the count honest.

Store unopened mini tubs in their outer box
Check lids on any tub that has been opened
Keep the box flat so lids are not pressed sideways

Keeping the table and the carpet out of it

Our compound releases from skin cleanly, but pigment is pigment. On a hard table it wipes away with a damp cloth. On carpet, upholstery or an untreated wooden surface it works into the fibre and stays.

Two swirl-filled slime tubs open on a wipe-clean surface

A placemat or a tray solves this permanently and costs nothing. It also gives the session an edge, which turns out to matter: a tray is a boundary a four-year-old understands better than an instruction.