What are bingsu beads made of?

Our stock bingsu is PET — resin identification code 1, and practically insoluble in water, which is why the strands keep their shape in a wet slime base instead of softening. They are soft and very light, giving a fine crunch without weight.

How many jars does 500g of bingsu beads make?

It depends entirely on your dosing, so measure rather than guess: weigh the filler in one finished jar at the density you like, then divide 500 by that figure. Because bingsu is light, 500g goes considerably further than a dense filler.

Will iridescent fillers bleed colour into pale slime?

It can happen, and usually shows up after days rather than immediately. Test a pinch in your palest base, sealed and kept warm, checking at 24 hours and again at a week. Test per batch, not per supplier, because pigment lots change.

Are clay sprinkles a filler or a topping?

A topping. Polymer clay is a PVC-based material cured at around 129 to 135 °C, so it arrives as a fully cured solid that holds printed detail — that detail is only worth paying for where buyers can see it, on the surface.

Sourcing Guide

Bingsu Beads vs Fishbowl Beads vs Foam: A Filler Guide

Updated July 2026 · by the Qula Craft Sourcing Team — the people who quote and pack these lines every week.

Short answer: bingsu beads are soft, iridescent PET strands that give slime a crunchy-but-light texture; fishbowl beads are hard, rounded and louder; foam balls are the cheapest bulk volume and change the texture to floam. Our bingsu packs ship 500g per bag from one bag. Pick by the sound and stretch you are selling, then match the topping to it — not the other way round.

Finished slime jars topped with bingsu beads, sprinkles and charms — Finished jars — the filler decides the sound and the texture, not the topping.

1. The three fillers, side by side

Filler	Material & feel	What it does to the slime	Watch out for
Bingsu beads	Soft PET strands, iridescent, very light	Fine crunch with almost no weight; keeps stretch	Colour can migrate into pale bases — test before a big batch
Fishbowl beads	Hard rounded plastic	Loud, obvious crackle; adds visible volume	Sinks and pools at the bottom of a jar on the shelf
Foam balls	Expanded foam, various diameters	Turns the base into floam; cheapest way to add bulk	Changes the product category — floam buyers and slime buyers differ

Our stock bingsu is listed as PET. That matters more than it sounds: PET carries resin identification code 1 and is practically insoluble in water, which is why the strands hold their shape in a wet slime base instead of softening into mush the way some cheaper substitutes do.

2. What 500g actually covers

Both of our bingsu packs are 500g per bag, minimum one bag. Because bingsu is so light, 500g is a lot of visible volume — considerably more jars than 500g of a dense filler would cover. Rather than guess at a jars-per-bag figure that depends entirely on your dosing, do it the reliable way:

Weigh the filler you put into one finished jar at the density you actually like.
Divide 500 by that number. That is your jars per bag, for your recipe.
Re-check after the first production run — most makers use less than they expect once they see it in the jar.

This is the same reason we sell trial sizes on the sprinkle side of the catalogue: guessing dosage from a photo is the fastest way to end up with dead stock.

3. Colour bleed is the failure mode that costs a batch

The single most common complaint about any iridescent filler is colour migrating into a pale base after a few weeks on a shelf. It is not always visible on day one, which is what makes it expensive — you find out after the batch has shipped.

Test it in 20 minutes before you commit: put a pinch of filler into your palest base, seal it, leave it somewhere warm and check at 24 hours and again at a week. If the base has picked up a tint, keep that filler for saturated colours only. Do this per batch, not per supplier — pigment lots change.

4. Filler versus topping — they are different jobs

Fillers change the texture and sound of the slime and get mixed through. Toppings sit on the surface, sell the photograph, and are usually clay or resin. Confusing the two is why some jars look great and feel wrong.

Clay sprinkles are a topping, not a filler, and there is a physical reason: polymer clay is a PVC-based material that cures at roughly 129–135 °C — it is a fully cured solid by the time it reaches you, so it holds its printed detail on the surface where buyers see it, rather than being worked through the base where the detail is wasted.

5. A filler range that does not overstock you

You do not need every filler. Most shops that reorder steadily run one crunchy filler, one visual topping range and one seasonal set, then rotate the seasonal slot four times a year. Concretely: one bingsu pack for the crunch, a clay sprinkle mix for the surface, and a themed charm set that changes with the calendar.

Everything above ships from one bag, so you can build that three-part range for a first order without committing to bulk on any single line — then scale only what sells through.

Test before you scale: pinch of filler into your palest base, sealed, checked at 24 hours and one week. Do it per batch — pigment lots change, and colour bleed does not show on day one.

Get a filler quote with your texture in mind

Tell us the texture you sell — light crunch, loud crackle, floam — and the base colour. We quote by the bag with carton data attached, and can send trial quantities before you commit to a season.

Request a slime filler quote →

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