Understanding Countertop Seams: What You Need to Know
October 16, 2023
Perry Seams


Discover why seams are used in your kitchen, how they are placed in your countertops, and what a good one looks like.

In the process of countertop fabrication and installation, the topic of seams often arises in the layout step. They are often thought about negatively, but whenever a seam is placed here at Mogastone, it surely is necessary. Let’s take a look at the purpose of seams, where and how they are placed in a countertop, and what an excellent one looks like.

What is a Seam?

A seam is a connection of two countertop pieces to make one full surface. Unfortunately, although they are often undesired, they are often also required. There are many reasons for this as we will see in the next section.

A bar like this with such a massive length will need multiple seams. The full backsplash will also need some. Because of its large size, even the island has one in it.

Why are Seams Used?

Seams are used for many reasons. One reason may be that the countertop does not fit through a door way. It could also be that it would endanger the customer’s home or the installation crew.

Another reason could be that a customer chose a material that isn’t particularly durable. An absence of a seam could cause the counter to crack during the installation or the fabrication process.

An alternative need for a seam could be the difficulty of getting a long piece between two walls. Imagine how difficult it would be to get a long, precisely measured countertop placed down when you need to slide it through surrounding walls. It is virtually impossible not to damage something in that process. The counter would, therefore, need a seam, so the crew could place two separate pieces.

One more reason, which is probably the most common, is the issue that the length of a desired countertop exceeds the length of a slab. For example, take into account that a slab is generally about 125 to 130 inches long. If a counter is 135 inches, for instance, it is impossible to fit it into a slab without a seam. 

How and Where is a Seam Placed?

Whenever we need to put a seam in your countertops or backsplash, we always take careful measures to ensure we put them in wise places. For example, it is generally not a good idea to place one in a spot like above a dishwasher or through an overhang. The reason for this is because it is unsupported and can shift out of place. In the case of overhangs, we can place an extra bracket to support the seam.

We also do our best to make sure they are as inconspicuous as possible. This means doing things like vein matching and making sure multiple seams aren’t in too close of a proximity. It also means ensuring they are avoided as much as possible in the most used areas of the kitchen.

Customer House Example

This is a kitchen that we fabricated and installed in October 2022. We will use it as an example in this blog article to show placement and necessity of seams. First of all, this is a large mitered Paonazzo island. This island was so large that we had no choice but to put a seam down the center of it. But the seam did little to affect the natural elegance of the marble.

Island Seam

Notice the red line in the center of this Paonazzo island. This marks the placement of seam in this image.

In the image below, we marked all the seams existent in the kitchen with red just like we marked the island in the image above. There are a total of eight seams in this kitchen. There are three connecting the countertops and four connecting the full backsplash, and there is one in the island.

Perry House Seams

Eight marked seams in a Paonazzo marble kitchen.

Now let’s get to the part of how a seam is actually placed. In today’s digital world, making a seam on your countertop can be done in a few clicks of a mouse. The only difficult part is making sure that the veins of the two pieces match. This process can some time, especially with higher level natural stones.

Layout GIF 11

Making a seam in Slabsmith.

A Good Vs a Bad One

There are many factors that differ between a well made seam and badly made one. Some factors that are important to take into account are vein matching, color similarity, and levelness.

Porcelain Seam

Marked Porcelain countertop.

The image above shows a nearly perfectly matched seam. The reason we were able to match it so close is because the material is porcelain which is an engineered material. A manufactured stone cannot be as diverse as a natural stone. So, engineered material can make seam matching easier, but it can also make it harder. It depends on how similar the slabs are.

Taj Mahal Seam

Not an excellent seam on this Taj Mahal overhang.

There are a few things that aren’t very good with this seam. First of all, the veins don’t match well, and the veins are flowing in different directions. The seam is also considerably long and cut through an overhang.

Although this seam has such issues, it was necessary for us to make. The reason for this is that the slab was shorter than the length of the countertop, so we had no choice but to put a seam through the overhang. Also Taj Mahal is a quartzite that has a very similar color across the whole slab, so while the seam is neither in the best place (in this case it was because of our limitations) nor are the veins flowing the same way, it is still acceptable.

A bad seam overall is one where the veins neither match nor flow the right way. It is also where the colors of the two pieces don’t match, and it is in a very visible area or is unnecessarily long. Plus, the epoxy color is different, and/or the seam is not level.


Seams are not all bad; in fact, making the right decisions in placement and vein matching can make them look rather appealing. Although the idea of seams in kitchen countertops isn’t a very exciting thing, they are sometimes necessary. They’re just something we have to live with when it comes to kitchen countertops. However, here at Mogastone, we will do the best we can to avoid seams or make them as good as possible.

You May Also Like…