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How to use modelling paste

Updated: October 2026

The tub is open and the knife is in your hand. The usual failure is a thick single coat, or paint laid over a skin while the core is still wet. That coat cracks, or it stays soft. This is how to use modelling paste: stir if it has settled, lay a layer you can dry through, wait, then paint. Which tub to buy is on our [Structural paste](/hub/painting-supplies/structural-paste) comparison. If the doubt is the stretched canvas, use the [modelling paste on canvas](/hub/painting-supplies/structural-paste/sub/structural-paste-on-canvas) page. Peter F. used the amazon.co.uk extracts on 16 October 2026 and did not time a drying test. A qualifying purchase can earn a commission at no extra cost to you.

The tub is open and the knife is in your hand. The usual failure is a thick single coat, or paint laid over a skin while the core is still wet. That coat cracks, or it stays soft.

Our top picks

Liquitex Liquitex Flexible Modeling Paste 473 ml

Best overall

Liquitex Liquitex Flexible Modeling Paste 473 ml
8.5/10about £21.20
View offer
Kreul Kreul Solo Goya coarse sand 250 ml

Alternative

Kreul Kreul Solo Goya coarse sand 250 ml
7.3/10about £16.86
View offer
Mont Marte Mont Marte Modelling Paste 500 ml

Preis-Tipp

Mont Marte Mont Marte Modelling Paste 500 ml
8.2/10about £13.05
View offer
On this page
  1. 1.Knife, support, and a stir if the tub has settled
  2. 2.How thick a layer, and why one coat fails
  3. 3.Drying without sealing the core
  4. 4.Paint, tint, cracks, and cleanup

Knife, support, and a stir if the tub has settled

Use a palette knife or a stiff tool, not a soft brush, when you want the paste to stand up. Mont Marte's tips describe a knife, a strong support, drying before you paint, and washing tools while the paste is still wet. If the tub has sat, stir it. A watery layer on top is not a sign that the whole jar is too thin. A stretched canvas moves and a heavy load can sag it. A board does not. If your paste is the hard, rigid-support type, as Liquitex Basics is, move to a board. This page assumes the support can take the layer you are about to lay.

How thick a layer, and why one coat fails

Build in layers. One thick coat is the mistake the bullets invite, because 'no cracking' and 'crack resistant' read like a permit. They are not. A Liquitex flexible-paste how-to sheet says layers no more than about 6 mm, dried slowly, and that drying too fast causes cosmetic cracks. That limit belongs to the flexible Liquitex paste. Do not turn it into a rule for Kreul coarse sand or for Marabu gold. If you want a high ridge, lay a layer, let it dry through, then add the next. Filling a crack later is easier than sealing a wet core under paint.
Liquitex Liquitex Flexible Modeling Paste 473 ml

Testsieger

Liquitex Liquitex Flexible Modeling Paste 473 ml
8.5/10about £21.20
View offer

Drying without sealing the core

Read the field on your own tub, then treat a thick film as slower. Kreul prints 6 hours. Liquitex and both Kamenskaya listings say 24 hours for a full cure. Nicpro and RICH print a quick-drying bullet and no hour. Mont Marte has no dry-time field. One UK text was still wet after 8 hours against a direction of about 30 minutes. Thick Liquitex jobs in these texts mention 48 hours and about 72 hours. Do not paint the skin if the middle is still soft. Mont Marte's tips say a hair dryer can speed drying. Liquitex UK's notes on the hard Basics paste treat a rushed dry as a cause of cracks. Match the advice to the paste you opened.

Paint, tint, cracks, and cleanup

White paste lightens acrylic if you mix it in. If the hue must stay true, paint over the paste when it is dry through. None of these extracts says you may stir the paste into oil colour. If a layer cracks, let it finish drying, then fill it with a thin coat. Wash the knife before the paste dries. Liquitex UK's flexible page says the paste contains MBIT and may produce an allergic reaction. Do not call a non-toxic bullet allergy-free. Stop when the support is a rented wall, a ceiling, or a wet room. If the tub is the wrong body, use the modelling paste buying guide.

Common questions

Do I use a brush or a knife?
Use a knife or a stiff tool when you want relief. A soft brush spreads a creamy paste into a thin film and hides whether it can hold a ridge. Mont Marte's tips describe a palette knife. Spread, then leave the mark. Do not keep working a layer that has started to skin.
How thick can one layer be?
For Liquitex flexible modelling paste, the maker how-to says no more than about 6 mm, dried slowly. That figure is not a rule for coarse sand or for a 100 ml gold paste. A bullet that says the paste will not crack is not a thickness permit. Add the next layer only after the first has dried through.
Can I force it dry with a hair dryer?
Not as one rule for every tub. Mont Marte's tips say a dryer can speed drying. Liquitex UK's notes on the hard Basics paste treat a rushed dry as a cause of cracks and suggest loose plastic wrap. Match the advice to the paste you opened. A UK Mont Marte text was still wet after 8 hours against a 30-minute direction, so a short blast is not a cure time.
When can I paint over it?
When the core is dry, not when the surface feels dry to a fingertip. Kreul prints 6 hours. Liquitex and both Kamenskaya listings print 24 hours for a full cure, and thick UK Liquitex jobs in these texts waited longer. If you paint a skin over a wet middle, the coat can crack or stay soft.
What if it cracks?
Let the crack dry, then fill it with a thin layer. Liquitex UK's Basics page says the same for that hard paste: fill after drying, and do not rush the dry. A German report that RICH cracked is not a UK review and is not proof that every white tub will split. Thickness and speed are the two causes you can change on the next layer.
Which dry-time on the tub should I trust?
Trust the printed field as a thin-film claim, then add time for a thick coat. Six hours on Kreul and 24 hours on Liquitex and Kamenskaya are listing fields. A 30-minute direction that failed in one UK Mont Marte text is a reason to test an edge. Quick-drying bullets with no hour, on Nicpro and RICH, are not a clock.

Related pages

Modelling paste vs gel medium

Structural paste

Best modelling paste: a buy-if, a skip-if, no crown

Modelling paste buying guide for four different bodies

Modelling paste on canvas: flex, sag and thin peaks

Sources

Public UK sources on CLP labelling, VOC scope for building coatings, satisfactory quality, and workplace COSHH. Shelf prices, stars, and review counts are the amazon.co.uk lines in the nine listings dated 16 October 2026. Prices move.

  1. Liquitex UK, professional flexible modelling paste (retrieved 16 October 2026)
  2. Liquitex UK, Basics modeling paste (retrieved 16 October 2026)
  3. Winsor & Newton UK, professional acrylic modelling paste (retrieved 16 October 2026)
  4. Daler-Rowney, System 3 texture paste (retrieved 16 October 2026)
  5. The Volatile Organic Compounds in Paints, Varnishes and Vehicle Refinishing Products Regulations 2012 (retrieved 16 October 2026)
  6. GB CLP, assimilated Regulation (EC) No 1272/2008 (retrieved 16 October 2026)
  7. Consumer Rights Act 2015, section 9 (retrieved 16 October 2026)
  8. HSE, COSHH (retrieved 16 October 2026)