Acrylic Retarder: How to Slow Down Acrylic Paint Drying

Acrylic paint dries fast, especially in Sri Lanka’s warm weather, which can make smooth blending difficult. Acrylic retarder is a medium that slows down drying so you have more time to blend colours, soften edges and work wet-in-wet. This guide explains how it works, how much to use and the mistakes to avoid.

What does acrylic retarder do?

Acrylic paint dries as its water evaporates. A retarder slows that down, giving you a longer “open time” while the paint stays workable on the canvas and palette. It is especially useful for portraits, skies, gradients and any painting that needs smooth transitions between colours.

The retarder we stock

FUJIN Acrylic Retarder 100ml slows the drying of acrylic paint for easier blending. Mix in small amounts as directed on the label. Prices change, so see each product page for today’s price.

How much retarder should you add?

A little goes a long way. As a starting point, many paint makers suggest roughly 1 part retarder to about 7 parts paint (around 10–15%), and you should never go beyond the amount recommended on your bottle. Too much retarder can leave the paint soft or tacky for a long time and weaken the paint film.

How to use acrylic retarder, step by step

1. Squeeze out your paint on the palette.
2. Add a few drops of retarder to the paint and mix well with a brush or palette knife.
3. Paint and blend as normal. You will notice the paint stays workable longer.
4. If the paint starts to feel tacky or “grabby”, add a tiny drop of water on the palette rather than more retarder.
5. Let the painting dry fully in a ventilated room before adding thick layers, taping or varnishing.

Common mistakes

• Using too much: the paint stays sticky and may never dry properly.
• Using it as a thinner: retarder slows drying; it is not for thinning. Use a little water or an acrylic medium to change consistency.
• Brushing into half-dry paint: once paint has started to set, working over it lifts and tears the surface, retarder or not.
• Expecting oil-paint open time: retarder helps a lot, but acrylic will still dry much faster than oil paint.

Other ways to keep acrylic paint wet longer

• Squeeze out small amounts of paint at a time.
• Mist your palette lightly with water from a spray bottle.
• Use a “stay-wet” palette: a damp sponge or paper towel under baking paper in a shallow tray with a lid.
• Paint away from fans, air conditioning vents and direct sunlight.
• Choose larger tubs, which skin over less than small, half-empty tubes.

What else you need

• Acrylic paint: see our acrylic paint guide, or browse Mont Marte Acrylic 100ml.
• Soft blending brushes: filbert and flat synthetic brushes; see our paint brush guide.
• Mixing: a mixing tray with thumb hole and an artist palette knife.
• Other mediums: Art Rangers Gloss Gel adds body and gloss, and FUJIN Acrylic Varnish protects finished work. Browse all painting mediums.

Frequently asked questions

Does acrylic retarder change the colour?

Used in small amounts as directed, it shouldn’t noticeably change colours. Always test on scrap first.

Can I add retarder to any acrylic paint?

Yes, it is made to mix with acrylic paint. Follow the label for the amount, and test with your brand of paint.

Can I use retarder with oil paint or watercolour?

No. Acrylic retarder is only for acrylic paint.

Do you deliver islandwide?

Yes. We deliver across Sri Lanka in 2–5 working days, with cash on delivery, card or bank transfer. You can also visit our shops in Boralesgamuwa and Horana, open every day from 9 AM to 6 PM.

Not sure what to choose? WhatsApp the Haanz team on 0711 515 515 and we’ll help you choose the right paints and mediums.

More Haanz Art Guides

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