Images are a great way to spruce up your email marketing; they make emails much more visually interesting than plain text, and often increase engagement metrics as a result. However, sometimes email marketers take this desire to design flashy emails too far, and end up turning the entire email into one big image. While these image-only emails may be very visually appealing, they also come with some big disadvantages that you may want to consider before jumping aboard the image-only email marketing train.

Why can too many images hurt your email marketing engagement? There are a few reasons for this. The main reason is that the majority of email providers initially block images for security purposes. This means that, when someone receives your email in their inbox, they will only see blank spaces where your images should be. They have to go through the trouble of enabling images for your email before they can view it properly. If all of your email content is contained within those images, then readers may not have any reason to enable images in the first place, since they don’t know what’s in it for them. This will decrease open rates and click-through rates on your email marketing.

Another factor to consider is that large images usually mean large file sizes, which translates into longer loading times for your email. Even if your images aren’t blocked, people may get impatient waiting for your email to load and move on to something else. Email users, especially those reading emails on mobile devices, are notoriously impatient, so fast loading time needs to be a priority for any serious email marketer. Large images simply aren’t conducive to this.

Finally, it is important to remember that, more than ever, people are reading emails on many different screen sizes, and different mobile devices interpret emails differently. For instance, iPhones resize emails to fit on the screen, so no scrolling is required; however, this also means that the text in your images will be much too small to read. Android phones, on the other hand, do not resize images, so the text may be readable, but people will have to scroll quite a bit to get the full message.

So, what can you do to avoid this dilemma? A good rule of thumb is to balance images and text in your email marketing. You don’t have to eliminate images entirely from your email marketing, but make sure that your entire marketing message is not contained in those images either. If you provide both text and images in your email marketing, then the text gives people a reason to enable your images and see what you’re all about. The text will also adjust automatically to be readable on different screen sizes.

Another thing you can do is add descriptive alt tags to your images. Many email providers allow readers to see an image’s alt tag before the image itself is enabled. This means you can use that space to entice people to enable images on your email; you can include any offers or discounts, product descriptions, or even your company’s slogan. The point is to not leave your readers in the dark about your email’s content.

To keep loading times down, try to include several smaller images in your email marketing instead of one very large image; an image with smaller dimensions usually results in a smaller file size. We generally recommend keeping all image widths at 600 pixels or less. Not only will this keep file sizes down, it will also ensure that your emails display properly across email programs. You should also try to use image formats that generate smaller file sizes, (a JPG or GIF is usually smaller than a PNG).

Ultimately, people will not read emails unless they feel it is worth their time and energy, and by designing your email creative as one big image, you are denying them the ability to evaluate its usefulness to them. As tempting as it can be to design very flashy emails, make sure you don’t shoot yourself in the foot by making that your sole priority. It is possible to design email marketing that is both flashy and utilitarian; striking a balance between images and text is key. By using the tactics above, you can design beautiful emails that will actually get read and clicked on. Happy emailing!