Using Powertex on plastic and other questions

Powertex Universal Medium can be used on almost any surface and for a range of art or craft projects. It’s different from some other art supplies so I’m answering some of the questions that come up about using Powertex.

Can I use Powertex on plastic and other questions

Here are some of the questions I’ve come across as a Powertex artist and tutor, about using Powertex.

When I say “Powertex” I mean Powertex Universal Medium.

Can I use any fabrics with Powertex?

The quick answer is yes, but not all fabrics will behave the same! Natural fibres work the best with Powertex if you’re looking to create a hardened sculpture or texture. The more synthetic fibres in the mix, the less the fabric will harden. Aim for at least 70% nature fibres for the best results. Synthetic fabrics will stay more flexible even when dry and cured. They will also be less weather resistant so keep that in mind if you’re creating something for outside.

If you’re using Transparent Powertex with fabric it’s worth doing a test piece first as it might darken the colour of your fabric.

What other materials can I use with Powertex?

Stick to natural materials to get the best from your Powertex as a fabric hardener, adhesive and paint. Fabrics and textiles such as muslin, cotton sheeting, hessian, stockinette and denim can all be used and have unique textures. But try what you have, including remnants and scraps.

Try adding wood, mdf, chipboard, cork, metal, aluminium wire, string or threads, t-shirt yarn, cotton yarn, silk flowers, feathers, raffia, heavy card or paper, paper clay, glass, sand or stone (and there’s more I haven’t thought of)! There’s a range of dry texture mediums available in the product range too.

You can also use acrylic paint and inks and decoupage with thin papers on Powertex surfaces.

Can I use Powertex on plastic?

Powertex does not stick well to plastics. Soft plastics can be particularly unstable. If I pour my Powertex onto a plastic plate and leave the leftovers to dry, the Powertex appears to stick to the plate. I can turn it upside down even. However it starts to peel away if I bend the plate or with minimal help from a palette knife. If you want your project to last, to go outside or certainly if it’s for sale I recommend you prepare your plastic surface first or use something else. 

How do I prepare plastic surfaces for Powertex?

Plastic shapes such as flower pots, bottles or boxes can be covered with masking tape which provides a surface suitable for Powertex. On intricate items masking tape may be too fiddly. Spray primers for plastic are available for these type of projects if you need your work to be lasting. I’ve also used gesso with success.

I’ve heard hairspray also suggested. I haven’t tried this but perhaps it gives the surface a “tooth”. However, the silicone content of the hairspray might not be the best base for your Powertex if you want a project to last. For short term projects this will work well enough.

Will Powertex stick to glass?

Yes it will. If painted on, the Powertex may bead on the smooth surface but a repeat application will usually help with this. Light weight fabric such as muslin makes a good first layer if you’re using fabric. Masking tape can be used if it can be hidden and is useful for bottles and wine glasses. If you’re using a fabric wrapping technique be sure your fabric is not over saturated with Powertex, your fabric should be tacky, not dripping!

Is Powertex waterproof?

Powertex Universal Medium is weatherproof and water resistant  when cured (after 3 weeks). Cured Powertex can resist bad weather including rain but it should not be submerged in water. It is not considered waterproof.

Projects for outside should be made with Powertex Universal Medium and natural fibres for best results. Easy Varnish can also be used as a top coat, as this is weatherproof. Easy Varnish should be used to protect any colour you add on top of the Powertex.

Note: Original Transparent Powertex is not weatherproof. Although a weatherproof version is available from February 2024.

If I decorate glasses can I wash them?

Projects like glasses can be washed with warm soapy water, rinsed and left to dry but should not be submerged in water or put in the dishwasher. Warm water may cause the Powertex to soften but will harden again when cool.

Are Powertex products safe for use with candles?

I strongly recommend that battery LED candles or lights are used with Powertex projects. Your fabrics and materials remain flammable despite the Powertex.

My Powertex has separated and it’s solid inside the bottle. Is it wasted?

Not yet! It is very common for Powertex to separate when it’s been left standing which is why you should always shake the bottle before use. There are things you can try to save your Powertex.

The solid contents will soften when warm so stand your bottle in a bowl of hand hot water until it’s warm. Then you will need to stir the contents. Use a long paint brush handle, dowl or similar and break up the solids inside the bottle. Give the mixture a really good stir. You may have to repeat the heating and stirring a few times. Mix your Powertex well and you’re good to go.

It’s worth remembering that Powertex starts to cure when exposed to air so don’t leave the bottle open unnecessarily.

Got more Powertex questions?

Powertex products are very versatile and Powertex artists and crafters are creating extraordinary things all the time. Try the Powertex Studio Facebook group run by Powertex UK where you will find, inspiration, help and UK tutors running workshops.

[Updated January 2023]