Why a side-by-side view beats flipping between two photos
In the practice of recording pottery results, the primary goal is often to establish a reliable baseline for what a specific combination of materials and heat can achieve. However, a significant challenge in visual documentation is the unreliability of human memory when attempting to judge subtle differences over time. When a potter compares a new result to a previous one, they are often forced to look at one photo, navigate away, and then view another.
From an information-design perspective, this “flipping” method is highly inefficient. Relying on a mental image while looking at a physical piece or another digital photo introduces a high margin of error. Subtle shifts in the depth of a glaze, the way it pools in textured areas, or the specific “break” of a color over a rim can be difficult to quantify if the two images are not held in the same visual field. Memory alone does not scale across dozens of firing-process entries, especially when the goal is to diagnose whether a specific change in conditions produced a genuinely different outcome.
A side-by-side comparison eliminates the need for mental reconstruction. By overlaying two images or placing them in a direct relationship, the potter can move past vague impressions—such as “this looks a bit glossier”—and engage in a more precise visual review. Without a direct comparison axis, these subtle variations are easily missed, making it harder to build a reproducible studio repertoire.
How the comparison works
To address the limitations of standard photo galleries, we built a comparison tool that displays two firing-log photos from the same work using a drag-based slider: moving a central divider across the screen reveals more or less of each photo at once, over the same area of the piece, which shows exactly how two results align or differ in a way that switching between two static thumbnails doesn’t.
What it’s useful for
The core idea — putting two photos in the same visual field instead of relying on memory to bridge them — is useful for two scenarios that come up in any studio practice, tool aside.
The first is judging the impact of a process change: comparing two different firing attempts on the same piece. If a work is re-fired to fix a surface defect or adjust the glaze’s maturity, logging each attempt with a photo and then viewing the two side by side (interactively or otherwise) makes it much easier to tell whether the second firing actually helped or the change was negligible.
The second is reviewing a piece’s evolution across stages — comparing the raw state after a bisque firing to the final result after the glaze firing, to see how the clay’s texture relates to the final glaze fit. In both cases, the comparison is a recording and analysis aid: it shows you that a difference exists, but interpreting why it occurred remains a matter of the potter’s own technical knowledge.
How KilnNote handles this
We built this comparison as a dedicated slider interface accessible from a work’s detail screen menu, pulling only from firing-process logs that have a photo attached. It’s offered as a Pro feature, consistent with how we split basic logging (free) from deeper analysis tools in the app. Because KilnNote is a local-first app, these photo comparisons happen instantly on your device without the need for cloud processing, and they remain completely private to your own studio archive.
Whether you are looking at how two different glazes reacted on a single test form or verifying if a re-firing improved a piece’s finish, the comparison slider provides the visual evidence you need to move beyond guesswork. You can access these Pro analysis tools and the core recording features by downloading KilnNote on the App Store.
Summary
The ability to compare two firing results side-by-side using an interactive slider is a powerful way to spot the subtle glaze variations that are often lost to memory. By building this tool as an analysis layer on top of a standard firing log, you gain a precise visual record of how your pieces evolve across different steps and firings. This structured approach to visual comparison is a vital part of building a reproducible and disciplined pottery practice.
For a broader look at how a comprehensive recording system can transform your studio management, see our hub article: That Glaze Combo You Can’t Reproduce: A Recording System for Potters
To learn more about how to set up the firing logs that provide the photos for these comparisons, see our guide on the firing process: What Actually Happened in the Kiln? A Firing Log System
For kiln operation and firing conditions, please follow your equipment manufacturer’s specifications and safety instructions.
This article organizes information from a recording and organizing perspective. If you notice an error or outdated information, please contact us. Last verified: August 2026
