Scanlines and phosphor masks make 240p games look right - if the scale is integer and the shader matches the panel. Two settings decide crisp or mush.
Turn on **integer scale**, pick **crt-geom** for a 1080p panel or **crt-royale** for 1440p and above, and switch **bilinear filtering off**. A shader on a non-integer scale turns the mask into moiré.
Open **Settings > Video > Scaling**, enable **Integer Scale** and set the aspect ratio to **Core provided** or **1:1**. Stretching to 16:9 destroys the geometry a CRT shader assumes.
Integer Scale: On
Aspect Ratio: Core providedLoad a preset from the shader menu: **crt-geom** is cheap and looks right at 1080p, **crt-royale** is heavier but resolves scanlines properly at 1440p and above.
crt-geom.slangp
crt-royale.slangpEnable **Hard GPU Sync** and disable **Bilinear Filtering**. The shader does the smoothing; the emulator's own filter only removes detail first.
Bilinear Filtering: Off
Hard GPU Sync: OnAperture grille looks best on high-DPI panels, slot mask on 1080p. If the image shimmers while scrolling, the mask is too fine for the pixel density - pick the coarser variant.
Scroll a fast game for a minute and check for drops. A shader that costs more than the core's budget stutters, especially at 4K with run-ahead active.
Save the settings as a **core override** so the shader stays with that system. A shader tuned for SNES is wrong for a 3D console.
Quick Menu > Overrides > Save Core OverridesInteger scale is off or the mask is too fine for the panel. Fix the scale first, then pick a coarser mask.
Bilinear filtering is still on, or the shader is being upscaled from a lower internal resolution.
The preset is incompatible with the current video driver. Switch between Vulkan and gl, then reload the preset.
Heavy multi-pass shaders add GPU time. Drop to crt-geom or disable run-ahead for that core.
Yes, they resolve better there. Use a sharper mask and keep integer scale on.
A single scanline overlay ignores the phosphor triad and the beam. A proper shader simulates both.
Load the **No Shader** preset, turn integer scale and the aspect ratio back to your defaults, and delete the core override if you saved one.
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