RetroArch Forum Buzzes With CRT Shader Presets and Bezel Pack Sharing

The Libretro forum's RetroArch Additions section logged one of its most concentrated weeks of shader activity in recent memory, with a six-day stretch from April 1 to 6 generating high-traffic threads on CRT presets, bezel packs, and device-specific configurations that drew thousands of views and dozens of downloadable files.

At the center of the surge was the long-running "Please show off what crt shaders can do!" thread, which functioned simultaneously as a rolling gallery and troubleshooting desk. Users posted comparison screenshots, traded parameter values, and linked to preset files hosted on GitHub and Gist. The format mattered: rather than describing what a shader does in the abstract, the thread let readers download and replicate results immediately.

The shader family drawing the most discussion was CRT Guest Advanced, the work of forum author guest.r. It now spans several variants, including the base crt-guest-advanced, a high-definition HD build, an NTSC version tuned for composite and broadcast signal simulation, and the lighter crt-guest-sm for devices with weaker GPU headroom. Forum user sonkun built a widely shared preset layer on top of guest.r's HD shader by pairing it with Dogway's color grading shader, producing Shadow Mask, Slot Mask, and Aperture Grille configurations distributed across three resolution tiers: 1080p, 1440p, and 4K. Shadow Mask and Aperture Grille presets land closest to consumer Trinitron and professional PVM looks; Slot Mask variants read more like arcade RGB output. All three require selecting the tier that matches the monitor's native resolution, or the results fall apart.

HyperspaceMadness's Mega Bezel Reflection Shader formed the backbone of most bezel pack posts. Mega Bezel bundles guest.r's CRT Guest Advanced as its default CRT pass and adds a reflection and border layer replicating the physical cabinet or television surround. CyberLab's Death To Pixels preset pack extends Mega Bezel further by incorporating Blargg NTSC video filters calibrated for specific systems, with Genesis and NES each getting dedicated configurations. A separate "Real GBA and DS-Phat colors" thread kept handheld users engaged, offering parameter sets tuned to the washed-out LCD characteristics of those screens rather than phosphor physics.

Stacking order proved a recurring subject across all of these threads. The method appearing most consistently was to apply an integer scaling pass first, then load the CRT mask and phosphor simulation, then add temporal smoothing last. Getting that sequence wrong, or skipping integer scaling entirely, produces halation artifacts and uneven scanline spacing at non-native resolutions. Bezel overlays carry their own installation pitfall: the CyberLab pack's folder placement was actively debated during the April window, with users clarifying that files must go into the Mega_Bezel_Community_Collections directory, not the older Mega_Bezel_Community path that earlier documentation still referenced.

For years, CRT shaders were something individual users tuned obsessively and almost never shared in a form others could replicate cleanly. What the April 1-6 activity represented was a volume of tested, resolution-specific, device-matched presets arriving in one place in a short window. That is not a subtle difference. Preservation-focused users who need consistent visual configurations across capture sessions now have a community converging around a small set of agreed-upon shader stacks rather than an endless field of personal tweaks. The shift from individual tinkering to shared, versioned preset packs makes the whole enterprise legible to someone picking up RetroArch for the first time, and that may be the most durable outcome of a very active six days on the Libretro forum.