Posca Pens on Glass: How to Seal Them Forever

You may have already known about the worldwide fame of Posca markers. They’re a brand that claims the ink is permanent once it is dried. But what about glass surfaces?

People often decorate glass items with acrylic paint markers and question their permanency.

So, have you ever thought to seal Posca pens on glass? Yes, it’s a great idea! But how do you seal them forever, so the design doesn’t get faded or wash away within a short time?

Well, there are so many ways of sealing Posca pens on glasses like – baking, varnishing, sealing, coating, and so on. But among them, I’m going to show you only the practical solutions that will last long.

That’s why in this article, I’ve come up with some ideas that will help seal your Posca pens on glass forever!

Seal Posca Pens on Glass

Why Do You Need to Seal Posca Pens on Glass?

The biggest reason to seal your Posca pens on glass is that they may fade or get washed away. It can really be a problem, especially if you’re planning to use the design for an important event like weddings, engagements, and other formal occasions where everything should happen according to plan!

It isn’t very pleasant when something breaks up all of a sudden at the very last moment.

That’s why people even want to seal Sharpie on non-porous surfaces, though they are already using a permanent marker.

In the same way, though the brand claims it to be permanent, when you use it on a non-porous surface like glass, it can cause fading of the art projects due to lightfastness.

Besides, the brand also claims that you can remove the ink from such surfaces if you want. So, people want to seal it permanently to avoid any unwanted situation like fading the ink color.

Since we need to use glass items like wine glasses, dinnerware, etc., in our daily lives, you should seal the design to use them longer. Even it’ll also make those designs dishwasher proof.

Ways to Seal Posca Pens on Glass (Best Methods)

Actually, there may have too many ways to seal Posca pens on glass surfaces. But here, I’m mentioning only the most effective ones that I have tried myself.

So, I can assure you that the result will be the same one you wanted. Let’s get in without any further delay!

Method 1: Varnishing is Great

Varnishing is one of the best ways to seal Posca pens on glass. You can easily use any of the water-based varnish sprays for this purpose. Though most of this varnish needs to just spray over the artwork, you can still follow the instructions given on the label.

After completing your design on glass items, let it dry completely before using the varnish. Then shake the bottle gently and spray over the paint from 30cm away. A proper one coat will be okay for this purpose.

However, many people tend to apply a second coat over the first one to ensure the artwork is safe.

So, if you also want to apply a second coat, let the first coat dry completely and then put another coat over it. In this way, you can use Posca pen ink for a more extended period.

Method 2: Baking Helps a Lot

Making the ink permanent can be easier with the baking method. But it’s not actually recommended for all types of glass items. The reason is, not all the products are oven-proof.

So, your design may ruin away if the thing breaks down due to not having the heat-resistant capability.

However, usually, you can heat the glass items slowly at 220˚ for 15-20 minutes. Then keep it inside the oven and let it cool down completely. Finally, take it out, and your designer item is ready to use. Again, I remind you that use oven-proof glass items for this purpose.

You can also fix the paint on porcelain using the same way, but to a temperature of 160° and for no more than 45 minutes.

Method 3: Resort to Nail Polish Coating

Another popular sealant is clear nail polish. You have to use it for sealing Posca ink in the same way you put a glaze on your nails. Yes, putting on coating over the Posca art is the only thing you have to do.

However, you just need to get a clear nail polish that you usually use on your nails. Get a branded one for a better result. So, just cap off the nail polish and use a generous amount of it to coat over the design you have created with Posca paint pens.

You can use the brush that comes up with nail polish for smaller areas. But for bigger spaces, you can use a medium size painting brush to save your valuable time. After getting the work done, you can clean the paintbrush with acetone.

Even you can use non-acetone clear nail polish coating over dry erase marker inks to seal it on laminated paper. It not only seals the ink but also makes it look glossy. So, you can easily use this item without any hesitation.

Method 4: Seal the Deal with Mod Podge

Lastly, don’t forget to try out the mod podge. You will get it in liquid and spray both forms. You can use any type you want. This type of sealer is really very easy to use. You just need to spray over the artwork and let it dry out properly.

And then you’ll see that the design will become permanent. Even you can use Windex over the Posca ink to test my words.


Before applying any color on the glass surface, make sure the area is free from dirt and grease. And don’t use second coats of spray varnish without drying the previous one. If you use baking, then make sure that the glass item is oven-proof or not.

Otherwise, any accident can happen due to the breakage of the item. And this sealing is not recommended for food use.


Q: Are Posca pens permanent on glass?

Posca pens are water-based acrylic paint markers that become permanent when it’s dried out completely. But it’s only valid for porous surfaces. Since glass is a non-porous surface, Posca doesn’t get the scope to be permanent on the surface that it is supposed to be.

So, if you want, you can scrape off the ink once it is dried thoroughly. However, if you’re going to make Posca permanent on glass, you can follow the above mentioned methods. Otherwise, the ink may wash off or fade away with time.

Q: Are Posca pens washable?

Long story short, Posca pens are washable if you don’t seal them properly. Whether it’s on a porous or non-porous surface, you can remove it following different methods. 

Though Posca pens act like permanent markers when you use them on porous surfaces, you can still remove them if you don’t use any varnish or sealers.

That’s why you can wash off Posca ink from fabrics if you accidentally got any. Even you can remove it from your skin or car windows.

However, when you seal it on non-porous surfaces like glass, the ink doesn’t wash off easily as it becomes permanent.

Q: Are Posca pens waterproof when dry?

Since Posca markers are water-based, many people ask, “Are Posca Pens Waterproof?” Well, it has no alcohol or other solvents, and maybe that’s why people get much confused.

But the truth is, it becomes waterproof once applied on the porous surfaces and is dried thoroughly. Even you don’t need any fixative to make it waterproof. 

The brand claims that Posca pens can be used on over 50 surfaces, and it becomes permanent when it dries on those surfaces. 

Q: What will write permanently on glass?

Actually, permanent markers are a good choice for writing on the glass. But Posca pens are also very popular, and they contain water-based ink. That’s why you need special sealants to fix it on the glass.

So, I would recommend you to use Sharpie markers to write permanently on glass. After going through all the Sharpie markers reviews, I recommend using Sharpie Oil-Based Paint Markers for glasses. It really works great! And you don’t even need to use any sealants to seal the ink.

Final Word

So, now you know how to seal Posca pens on glass! Just follow the methods mentioned above and impress everyone. Let me know in the comment section if you need any help or have anything else to share with us about this topic. 

I’ll be happy to assist you soon!

Feature Image source:Twitter @poscauk

Loard Eva

Hi there! I’m Eva, artist, designer, photographer and mom of three little gentlemen altogether. When I’m not playing with my kids, you’ll find me researching and writing for ChooseMarker.

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