Mix model paint with agitator balls: count and lid

You twist the lid off a Citadel or Vallejo pot and the colour has split: a thick pigment sludge under a watery layer. To mix model paint with agitator balls, drop a 5.5 mm stainless ball into a sound pot, shut the lid until it seats, and shake until the colour looks even again. The ball’s job is to travel through the liquid and disturb what has settled. It does not revive paint that has already dried into a solid lump.

This guide uses amazon.co.uk listing text and UK review notes for three 5.5 mm packs, recorded in October 2026: SZXMDKH B09Q8FCXSF, an unbranded pack B0F8LQ2P1Z, and REBECCAHOWARD B0H86ZMGDB. Peter F. did not run a lab test. Shelf prices were about £5.11, £4.71 and £4.66, and they can move. A qualifying purchase through our links can earn a commission at no extra cost to you.

In short

Put one or two 5.5 mm balls into a pot whose mouth will take them, close the lid, and shake. UK reviews on the SZXMDKH pack mostly describe one or two balls, with one reviewer using three in a 12 ml pot. Rinse and dry a ball before it changes colour. Only B0F8LQ2P1Z states 304 stainless steel. A magnet check does not certify the grade, and loose balls should stay away from young children.

Put the ball in before you shake

The ball goes in, the lid seats fully, and only then do you shake. An open bottle throws paint, and it can send a 5.5 mm steel ball across the desk. All three packs state 5.5 mm. If the opening is tighter than that, forcing the ball risks the neck. UK reviews on the top pick, SZXMDKH B09Q8FCXSF, name Citadel, Vallejo, Army Painter and airbrush bottles.

Press the lid until the thread is home. A lid that is only resting on the rim leaks as soon as the ball hits it. Shake along the bottle, then tip it so the ball travels from the bottom to the shoulder. Stop when the colour looks even. The single UK review on REBECCAHOWARD B0H86ZMGDB describes a remix of separated acrylic after about a minute, and that listing is rated 4.0 from one review. Judge your own pot by eye. How to hold a vortex shaker and check that lid is in the how to use a paint agitator guide. The paint agitator comparison is where vessel size picks the tool, from a hobby bottle up to a tin, a bucket or a drum.

How many balls in a 12 ml pot

SZXMDKH B09Q8FCXSF has 4.7 from 438 reviews, the broadest set of the three packs. Reviewers mostly use one ball or two. One reviewer recommends three in a 12 ml pot. Three is that person’s method. Start with one ball and the lid shut. If a ribbon of pigment remains, add a second and shake again. A second ball helps when the pot is only partly full and one ball spends its time in the air gap. Try a third in a 12 ml pot that still streaks after two, and stop if the pot feels packed or the lid takes a heavy knock. Each ball displaces a little paint.

Pack size is a different count. The SZXMDKH and B0F8LQ2P1Z titles both say 120 pieces at 5.5 mm. At one or two balls per bottle, that covers a sizeable rack. The REBECCAHOWARD title also says 120, but a technical attribute on B0H86ZMGDB says a unit count of 1. Confirm the quantity with the seller if you need a known number. Who should pick or skip each pack is on the paint mixing balls page.

Grade, rust, and a magnet

Only B0F8LQ2P1Z states 304 stainless steel in the bullets. That pack was about £4.71, rated 4.7 from 14 reviews, with an age line of 14 years and up. The bullets describe acrylic pigment separating from the resin. Oil paint is unestablished on that page. Choose this pack when the stated grade is the point. The 438-review history sits on SZXMDKH.

SZXMDKH B09Q8FCXSF was about £5.11 and does not state a grade. The seller text includes a salt-water rust claim, and one reviewer reported no rust overnight. Another reviewer used a magnet and described non-ferrous behaviour. Both notes are single household observations. A ball a magnet leaves on the table can still be a grade the page never names. REBECCAHOWARD B0H86ZMGDB was about £4.66. The one UK review reports no visible rust over several months in acrylic. One review is too narrow for a corrosion claim across a whole rack. If you need a verified composition, ask the seller for documentation. The agitator buying guide separates a bottle ball from a stirrer for a much larger coating.

Clean the ball before the next colour

If a bottle stays one colour, leave the ball inside between sessions, with the lid closed. That matches the way the reviews talk about balls living in Citadel and Vallejo pots. Moving a ball is where colour gets contaminated. Acrylic film dries on the steel as a skin you can miss in room light. Drop it into a white or a pale yellow and the last pigment shows up as a tint.

Rinse under water until the runoff is clear, then dry the ball before it enters the next bottle. Water left on the steel thins the paint at the bottom. Once you have shaken the new colour, a wash of the ball will not pull that tint back out of the bottle. The listings do not specify a solvent or a soak time. Water is the reasonable rinse for the water-based acrylics these reviews describe. Oil paint sits outside that evidence. Wipe the rim and the lid thread after a messy shake, then close the pot again.

Small parts and a cracked pot

A 5.5 mm steel ball is small, heavy for its size, and easy to miss on a table. The Office for Product Safety and Standards tells shoppers to follow age marks, because those marks reflect risks such as choking, and to avoid small parts around young children. B0F8LQ2P1Z prints a manufacturer recommended age of 14 years and up. That ASIN is ranked in Toys and Games while the page sells it as a paint tool. B0H86ZMGDB sits in the same toys ranking. Follow the age line on the pack that prints one, and keep a loose steel ball away from a young child.

On B09Q8FCXSF, two reviewers reported a cracked storage pot and still used the balls. Check that the balls are clean, then decide whether the broken container is worth a return. If your own paint pot is cracked, chipped at the rim or missing its lid, leave the ball out. Reviewers tie the SZXMDKH balls to hobby acrylic bottles. Oil, nail varnish, household emulsion and a 1 litre tin are outside the UK review notes collected here.