Pin Reference Image on Top of Other Apps (2026 Guide)

By refern. Last updated: June 2026.

You can float a reference image above Photoshop, Blender, Procreate for desktop, or any other application by enabling always-on-top mode in your reference tool. Three tools that do this well are PureRef, Kuadro, and refern. Each one also supports adjustable window transparency and mouse clickthrough, so you can paint or model directly under the floating reference without interrupting your workflow.

This guide covers:

1. What "pin on top" actually means and the three settings that matter
2. How to set it up in PureRef (best if you only need a canvas overlay per session)
3. How to set it up in Kuadro (best for individual floating windows on Windows)
4. How to set it up in refern (best if you also want a searchable library)
5. Comparison of all three
6. Common problems and fixes

Before You Start

Three settings work together to make an overlay reference useful. Understand them before touching any tool:

Always-on-top: The reference window stays in front of every other window, including your painting or 3D application. Without this, the reference disappears behind your app whenever you click into it.

Window transparency (opacity): The reference window becomes semi-transparent so you can see both your canvas and the reference at once. Useful when the reference needs to overlap your painting area rather than sit beside it.

Mouse clickthrough (paint-through): Mouse and stylus events pass straight through the reference window to whatever is behind it. You can paint, sculpt, or draw without moving the floating reference. This is the setting that makes overlays genuinely useful rather than merely convenient.

You do not need all three at once. Most artists use always-on-top with the reference beside their canvas and only enable clickthrough when they need to trace or sample colors.

Step 1. Choose Your Reference Tool

Each tool handles overlays differently. Pick based on your workflow.

If you only want a floating reference for a single session and do not care about building a library, PureRef or Kuadro are both excellent and free (or nearly free). If you want to reuse references across projects, tag them, search by color, and keep everything organized, refern adds those layers on top of the same overlay capability.

Step 2. Set Up PureRef as an Always-on-Top Overlay

PureRef is a canvas-based tool. You drag images onto a single board, then pin that board above your other applications. It is widely used in concept art and 3D workflows because of its focused design.

Open PureRef and add your references. Drag images from your file manager or browser directly onto the PureRef window. You can also paste from the clipboard.

Enable always-on-top. Right-click anywhere on the canvas to open the context menu. Go to Mode. Select "Always on top." The PureRef window will now stay above every other application including Photoshop, Clip Studio, ZBrush, and Blender.

Pin to a specific application (PureRef 2.0 and later). If you want PureRef to stay on top of only one app (for example Blender, but not your file manager), go to Mode and select "Always on top of application." Then click the target application. PureRef will remain pinned to that window specifically. This is a genuinely useful feature that reduces visual clutter on multi-monitor setups.

Adjust opacity. Right-click, go to Mode, and select "Opacity." Drag the slider to set how transparent the window appears. A value around 70 to 80 percent keeps the reference readable while letting you see your canvas through it.

Enable clickthrough. Right-click, go to Mode, and select "Transparent to mouse." In this mode, all mouse and stylus events pass through the PureRef window to whatever is beneath. You can paint directly under the reference. To interact with PureRef again (move images, scroll the canvas), disable this mode first.

One workflow note: PureRef saves as a .pur file that embeds your images. The board is self-contained and easy to email or archive. The limitation is that there is no search, no tagging, and no cross-project library. Each .pur board is standalone. If you find images to reuse later, you will need to locate them manually.

Step 3. Set Up Kuadro as an Always-on-Top Overlay

Kuadro works differently from PureRef. Instead of a unified canvas, each image opens as its own separate OS window. This makes it naturally suited to multi-monitor setups, where you can spread individual references across screens.

Download and run Kuadro. Kuadro is a portable .exe for Windows. Download it from kruelgames.com, double-click, and it is ready. No installation required.

Open your reference images. Drag and drop images onto the Kuadro window, or use File to open them. You can also paste a web image URL directly.

Enable always-on-top. Each image window has always-on-top mode on by default. If a window drops behind your app, right-click it and check that always-on-top is enabled.

Adjust opacity. Right-click an image window and use the opacity slider to make it semi-transparent.

Enable paint-through (clickthrough). Press the lock shortcut (check the Kuadro help for your version's key binding, typically a function key or right-click menu) to lock the image windows. When locked, all mouse events pass through to the application beneath. Note: Kuadro's lock mode applies to all open image windows at once, not individually. If you want some images movable and others locked, you will need to use a different tool for that workflow.

Kuadro's honest limitations. The macOS version is officially unsupported by the developer. No Linux version exists. Development has been very low activity since 2018 (with an unconfirmed later release around 2022). Kuadro has no library, no tags, no search, and no canvas. For artists who only need a handful of floating windows while they work, it is fast and free. For anyone building a growing reference collection, it does not scale.

Step 4. Set Up refern as an Always-on-Top Overlay

refern combines a full library (folders, tags, search, color search, smart folders) with an infinite canvas that you can pin on top of other applications. The overlay features match what PureRef and Kuadro offer, with the addition of a persistent library behind them.

Create a workspace. On first launch, refern asks you to point to a folder on your disk. This folder becomes your workspace. refern indexes the images already in it and adds new ones you import. It never copies your files; it reads and indexes in place.

Open the canvas. Create a new canvas from the canvas button in the toolbar, or open an existing one. The infinite canvas supports layers, groups, text, shapes, freehand drawing, and image filters.

Place your reference images. Drag images from your library onto the canvas. You can also drag directly from your file manager or browser.

Pin the canvas window on top. In the canvas window, click the pin icon in the toolbar (or use the View menu and select "Pin window on top"). The canvas window will stay above all other applications.

Adjust transparency. Once pinned, a transparency slider appears in the toolbar. Drag it to set the opacity. Lower values make the reference more transparent.

Enable mouse clickthrough. Click the clickthrough icon in the pinned canvas toolbar. Mouse and stylus events will now pass through the canvas to the application beneath. You can paint or draw under the floating reference. To interact with the canvas again, click the icon a second time to disable clickthrough.

Why the library matters here. The difference between refern's overlay and PureRef's is that the images you place on the canvas are drawn from a persistent, searchable library. You can search your entire collection by color, tag, filename, source URL, or visual similarity and then drag directly onto the canvas. Next week, those same references are still there, indexed and findable. You do not start from scratch each project.

Comparison of All Three Tools

Where PureRef wins. The "pin above a specific application only" feature in PureRef 2.0 is genuinely the best-in-class implementation of this workflow. If you primarily use references as a per-session overlay inside one application (ZBrush, Blender, Photoshop) and clear the board when you are done, PureRef is fast, free for personal use, and very well suited to that workflow. It is trusted, has 13 years of community adoption, and appears in art school curricula alongside the major applications.

Where Kuadro wins. For the simplest possible setup on Windows, Kuadro is hard to beat. Download one .exe, drag images in. Each image floats as its own window. No account, no setup, no cost. The paint-through mode works well. The main caveats are Windows-only, low development activity, and zero organization capability.

Where refern adds something different. If your reference workflow extends beyond a single session and you want to find those moodboard images from last month without manually browsing folders, refern is the tool that handles both. You get the same overlay and clickthrough, plus a library that scales to very large collections, full-text and color search, hierarchical tags, smart folders, and a browser extension for capturing references from the web in one click. The trade-off is a $30 one-time purchase after the 30-day trial.

Common Problems and Fixes

The reference window disappears when I click into my drawing app. Always-on-top is not enabled. In PureRef: right-click, Mode, Always on top. In Kuadro: right-click the image, confirm always-on-top is checked. In refern: click the pin icon in the canvas toolbar.

My stylus clicks are hitting the reference window instead of my canvas. Enable clickthrough (paint-through) mode. In PureRef: right-click, Mode, Transparent to mouse. In Kuadro: lock the windows. In refern: click the clickthrough icon on the pinned canvas toolbar.

The reference is too bright and distracts me. Lower the window opacity. All three tools have an opacity or transparency slider in their mode or view settings. For painting workflows, 60 to 75 percent opacity is a common starting point.

PureRef loads slowly with a large board. PureRef loads all images uncompressed into memory. The developers recommend splitting large boards into multiple smaller .pur files and enabling Auto Downscale in preferences. The issue is acknowledged by the PureRef team and has not been fully resolved as of June 2026.

Kuadro is not working on my Mac. The macOS version is officially unsupported by the developer. For Mac users, PureRef or refern are the actively maintained options.

I cannot find a reference I used last week. This is the core limitation of PureRef and Kuadro: neither has a library or search. The reference either lives in a .pur file you need to locate manually, or you need to find the original file through your OS file manager. refern solves this with a persistent indexed library: every imported image is searchable by name, tag, color, source URL, or visual similarity, regardless of when you added it.

Next Steps

Once you have the overlay working, the next step most artists take is building a system so the references they collect are reusable across projects. A few resources that help:

• What is a reference manager? covers the concepts behind organizing visual references at scale.
• refern vs PureRef goes deeper on where each tool is the better fit.
• Best PureRef alternatives for artists covers the broader landscape if neither tool fits your needs.

Conclusion

Pinning a reference image on top of your drawing or 3D application comes down to three settings: always-on-top, window transparency, and mouse clickthrough. PureRef, Kuadro, and refern all provide these. PureRef is best-in-class for the focused per-session canvas overlay and is free for personal use. Kuadro is the fastest zero-setup option for individual floating windows on Windows. refern brings those same overlay features together with a full library, search, and tags, so the references you collect today are findable and reusable next month.