384 ORIGINAL PREVIEWS · OCTOBER 30, 2026
Roblox Shirt Template Contrast Threshold: When a Thin Line Counts
A contrast cutoff changes the answer to “does this thin line show?” In our saved Roblox Shirt template preview test, the one-pixel source stroke counted as 42 changed pixels in every 64-pixel preview at RGB distance ≥64, but zero in every preview at ≥192. At ≥128 it ranged from 0 to 42 on a white/charcoal checkerboard. A zero count is only a result of the chosen cutoff; it does not mean the line vanished.
These cutoffs are our analysis settings, not Roblox upload or visibility requirements. We did not measure human recognition.
Same exported artwork, three cutoffs
We made two new transparent red-diagonal source images, 150 × 150 pixels, with one- and two-pixel strokes. Each went through this site's Classic Shirt editor at 45% Image size and its Download PNG control. Both exports measured 585 × 559 pixels. We cropped the same 128 × 128 FRONT square and smoothly scaled it onto 64 × 64 previews. Roblox's Creator Hub identifies the FRONT panel as a 128 × 128 square and recommends a Studio rig test for the garment.
Each export was drawn over white/charcoal checks, cream/slate checks, and solid white. Four-pixel checker tiles stayed fixed. We measured all 64 x/y offsets for each background, so 2 exports × 3 backgrounds × 64 offsets = 384 previews. For each pixel, we compared the preview to its matching blank background using √(ΔR² + ΔG² + ΔB²). We counted values at or above 64, 128, and 192 without changing the preview pixels.
| Saved stroke / background | ≥64: count range | ≥128: count range | ≥192: count range |
|---|---|---|---|
| 1 px · white/charcoal | 42 | 0–42 | 0 |
| 1 px · cream/slate | 42 | 0–3 | 0 |
| 1 px · solid white | 42 | 42 | 0 |
| 2 px · white/charcoal | 125–128 | 70–112 | 4–59 |
| 2 px · cream/slate | 124–128 | 62–104 | 0–42 |
| 2 px · solid white | 128 | 124 | 63 |
For the one-pixel white/charcoal preview, the zero-count share changes from 0/64 at ≥64 to 8/64 (12.5%) at ≥128 and 64/64 (100%) at ≥192. On cream/slate, the middle cutoff gives 12/64 zero-count offsets (18.75%). The wider stroke still has 4–59 counted pixels at ≥192 on white/charcoal, while eight cream/slate offsets reach zero. Solid white is a control: its 64 repeated offsets produce one visual condition.
What the measurement means
Raising the cutoff asks a stricter question of the same pixels. It cannot tell whether a person would notice the artwork, read a letter, or recognize the garment on an avatar. The 64-pixel preview is smaller than the saved FRONT panel; scaling and background both affect its RGB values. The 192 cutoff excludes even the one-pixel line on solid white in this experiment. Therefore a report that merely says “zero pixels” without naming its cutoff and background is incomplete.
A repeatable check for your own Shirt
- Download the actual PNG from the editor; do not substitute the placement guide or source logo.
- Crop the FRONT panel at x=128–255 and y=191–318 from the 585 × 559 Shirt export. Keep the same crop for comparisons.
- Preview it at the size you need over a plain background and over the intended patterned background. Keep the scaler fixed.
- Compare each preview to the matching blank background. If using a pixel threshold, state the RGB distance formula and cutoff. Check at several cutoffs before interpreting a zero count.
- If a detail appears weak in the preview, make it wider or simpler, export again, and compare under identical settings. Then follow Roblox's Studio Block Avatar test for garment appearance.
Method and limits
The reproducible browser script and full 384-preview readings are retained in the site project's audit folder as 2026-10-30-threshold-test.mjs and 2026-10-30-threshold-results.json. The numbers describe this red diagonal, these two widths, Chrome Canvas scaling, these three backgrounds, and Euclidean RGB distance. They are not a perceptual color metric or a Roblox standard. We did not conduct a blinded viewer test or a Studio rendering test.
Sources
- Roblox Creator Hub: Classic clothing — official FRONT-panel size and Studio test steps.
- Avatar Shirt Maker editor — import and Download PNG controls used in the original experiment.