A Guide to Handover's Oil-Based Gold Size : open times and tack time

At Handover, we take pride in offering high-quality products that our customers can rely on. Our oil-based gold size has long been a staple in our gilding range, and here we answer one of the questions we’re most frequently asked about working with this product.

Understanding Oil-Based Gold Size

Handover’s oil-based gold size is a clear yellow adhesive designed for traditional oil gilding, available in a range of open times from 1½ hours to 24 hours. We offer it in these different open times to allow users to choose the drying period that best suits their project needs. Within this open time there is a smaller period of time taken for the size to get ‘to-tack’ before it is ready to gild onto.

Tack Times Explained

One of the most-asked questions about our oil based gold size is how long it takes to get to tack – the answer is that this can vary widely depending on several factors, which is why we do not give set times on our website or packaging – so be aware, all the times dicussed here are not exact, and it is best to test before you begin your work!

Oil based gold size is ready for gilding when it reaches a tacky surface quality similar to the adhesive feel of cellotape or masking tape. A reliable method to assess this is by lightly tapping the surface with the back of your knuckle (rather than your fingertips, as oils from the skin can interfere with the adhesive properties). If there is a slight resistance as you withdraw your hand, the size has reached the appropriate level of tack.

Once it is tacky enough to start gilding, you then have the rest of the ‘open time’ as your working window during which the size will be tacky enough to accept gold leaf – for example, if the 1-2 hour size took 30 minutes to get to tack, you now have 1-1.5 hours left to work depending on temperature, etc.

If you do run out of time and the size gets too dry to use, don’t worry! You can start the whole process again once you have removed any skewings with a soft mop brush or cotton wool – any gaps can then be filled using the process above and the resulting gild can be lightly burnished to create a smooth finish.

These times (both to-tack time and open time) can vary greatly depending on temperature, humidity, substrate porosity, and method of application. Due to this variability, we strongly recommend conducting a test application prior to beginning work on a final surface, and monitoring the tackiness closely throughout the gilding process.

The to-tack time will be a small fraction of the overall open time, however, and we have a rough guide here:

• 1–2 Hour Size: Approximately 30-45 minutes to get to-tack, leaving 1-1.5 hours as a working window
• 3 Hour Size: Approximately 45 minutes – 1 hour to get to-tack, leaving around 2 hours as a working window
• 12 Hour Size: Approximately 4-6 hours to get to-tack, leaving around 6-8 hours as a working window
• 24 Hour Size: Approximately 8-14 hours to get to-tack, leaving between 10-12 hours as a working window. This variant fluctuates the most due to the long times involved

These times are guide only – please conduct your own tests before using, as the times can vary greatly.

Safety First

This product contains linseed oils and white spirit. Used rags can self-ignite without warning, so they should always be disposed of responsibly – ideally in a metal container filled with water or laid out flat to dry.

Learn more about gilding

If you want to learn more about how to use gold leaf and gold size (oil, acrylic, gelatin, etc!), we have a range of useful books to purchase on our website – two of note are Practical Gilding which provides a clear, approachable introduction to traditional techniques, and the more in depth Gold Leaf Techniques which offers a more detailed exploration of materials, methods, and applications.

Explore Our Range

You can browse the full range of oil-based gold sizes here >> to find the right option for your next gilding project. If you prefer to use an acrylic based size or even gelatin for a project on glass, we have lots of options for this available here >>.