--- title: "How to add a hollow outline text with Claude (tested prompt and script)" description: "A big \"GLOW\" fades in as thin hot-pink outlines with the video showing through the letters, then fills in solid pink from left to right. Install one skill and ask Claude Code, or run the Python script we tested yourself." url: https://www.recharm.com/effects/hollow-outline-text --- # How to add a hollow outline text with Claude A big "GLOW" fades in as thin hot-pink outlines with the video showing through the letters, then fills in solid pink from left to right. Made by the script on this page, from our own test clip. ## Get this effect 1. ### Switch to Code in your [Claude Desktop App](https://claude.com/download) 2. ### Install the skill (once) ``` Install the Recharm video effects skill: download https://recharm-growth-staging.s3.us-east-2.amazonaws.com/website/downloads/recharm-video-effects.zip and unzip it into ~/.claude/skills ``` 3. ### Ask for the effect ``` Add a hollow outline text to input.mp4 Word: GLOW ``` ## Several videos, several effects, one ask Put your clips in the folder, mention them with @, and ask for everything at once. Claude runs one tested script after another on each clip, then joins them. Add a hollow outline text to **@clip1.mp4**, put a sale badge on **@clip2.mp4**, give **@clip3.mp4** a VHS look, then join all three with crossfades. ## Settings you can change Ask Claude to change any of these, or edit them at the top of the script. | Setting | Default | What it does | | ----------------------- | ---------------- | -------------------------------------------------------------- | | `WORD` | `GLOW` | The word drawn. | | `Y` | `0.12` | Word center, as a share of the frame height down. | | `SIZE` | `0.25` | Font size as a share of the frame width. | | `COLOR` | `(255, 45, 140)` | Outline and fill color. | | `OUTLINE_WIDTH` | `4` | Outline thickness in pixels. | | `APPEAR, FADE` | `0.5, 0.3` | Second the outline fades in, and how long the fade takes. | | `FILL_START, FILL_TIME` | `1.5, 1.2` | Second the fill starts sweeping across, and how long it takes. | ## Without the skill Don’t want to install the skill? Paste this prompt into Claude Code and Claude writes the script itself. ``` Add hollow outline text to input.mp4: the word "GLOW" in Arial Black (or another heavy bold font) at a font size of 25% of the frame width, centered horizontally and 12% down the frame. Draw only its outline, 4 pixels thick, in pink (255, 45, 140), with the letters see-through inside; the outline fades in from 0.5 to 0.8 seconds. From 1.5 to 2.7 seconds the insides of the letters fill with the same pink, a hard edge sweeping from the left edge of the word to the right with ease-in-out, and the word stays solid pink to the end. Use Python with Pillow to draw the text (don't use ffmpeg's drawtext filter) and ffmpeg to put it on the video, keep the audio, and save it as output.mp4. ``` ## Run it without Claude This is the exact script we tested. Save it as `hollow-outline-text.py` and run: ``` python3 hollow-outline-text.py input.mp4 output.mp4 ``` ``` #!/usr/bin/env python3 """Hollow outline text: a big word appears as thin pink outlines only, then fills solid pink from left to right. Usage: python3 hollow-outline-text.py input.mp4 output.mp4 Needs ffmpeg and Pillow (pip install pillow). """ import json import math import subprocess import sys from pathlib import Path from PIL import Image, ImageChops, ImageDraw, ImageFont WORD = "GLOW" Y = 0.12 # word center, as a share of the frame height down SIZE = 0.25 # font size as a share of the frame width COLOR = (255, 45, 140) # outline and fill color OUTLINE_WIDTH = 4 # outline thickness in pixels APPEAR, FADE = 0.5, 0.3 # second the outline fades in, and how long the fade takes FILL_START, FILL_TIME = 1.5, 1.2 # second the fill starts sweeping in, and how long it takes to cross FONTS = ["/System/Library/Fonts/Supplemental/Arial Black.ttf", # macOS "/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf", # Linux "C:/Windows/Fonts/ariblk.ttf"] # Windows FONT_FILE = next((f for f in FONTS if Path(f).exists()), None) or sys.exit("No bold font found: add one to FONTS") def letter_masks(): """Two masks of the word: the outline ring alone, and the inside of the letters.""" font = ImageFont.truetype(FONT_FILE, round(w * SIZE)) pos = (w / 2, h * Y) inside, outer = Image.new("L", (w, h)), Image.new("L", (w, h)) ImageDraw.Draw(inside).text(pos, WORD, font=font, anchor="mm", fill=255) ImageDraw.Draw(outer).text(pos, WORD, font=font, anchor="mm", fill=255, stroke_width=OUTLINE_WIDTH, stroke_fill=255) return ImageChops.subtract(outer, inside), inside def overlay(t): img = Image.new("RGBA", (w, h)) fade = min(max((t - APPEAR) / FADE, 0), 1) if fade == 0: return img p = ease_in_out((t - FILL_START) / FILL_TIME) if p > 0: sweep = Image.new("L", (w, h)) ImageDraw.Draw(sweep).rectangle([0, 0, left + (right - left) * p, h], fill=255) img.paste(COLOR + (255,), mask=ImageChops.multiply(inside, sweep)) img.paste(COLOR + (255,), mask=ring.point(lambda v: round(v * fade))) return img def ease_in_out(p): p = min(max(p, 0), 1) return p * p * (3 - 2 * p) def probe(path): info = json.loads(subprocess.check_output(["ffprobe", "-v", "error", "-select_streams", "v:0", "-show_entries", "stream=width,height,r_frame_rate:format=duration", "-of", "json", path])) s = info["streams"][0] num, den = s["r_frame_rate"].split("/") return s["width"], s["height"], s["r_frame_rate"], float(num) / float(den), float(info["format"]["duration"]) def render(src, out): """Draw overlay(t) on every frame of src and save to out, keeping the audio.""" ff = subprocess.Popen(["ffmpeg", "-y", "-v", "error", "-i", src, "-f", "rawvideo", "-pix_fmt", "rgba", "-s", f"{w}x{h}", "-r", rate, "-i", "-", "-filter_complex", "[0:v][1:v]overlay=shortest=1,format=yuv420p[v]", "-map", "[v]", "-map", "0:a?", "-c:v", "libx264", "-crf", "18", "-c:a", "copy", out], stdin=subprocess.PIPE) for i in range(math.ceil(duration * fps)): ff.stdin.write(overlay(i / fps).tobytes()) ff.stdin.close() if ff.wait(): sys.exit("ffmpeg failed") src, out = sys.argv[1:3] w, h, rate, fps, duration = probe(src) ring, inside = letter_masks() left, _, right, _ = inside.getbbox() render(src, out) ``` ## More text and titles - [Animated text frame **Animated text frame**](https://www.recharm.com/effects/animated-text-frame) - [Brush stroke text reveal **Brush stroke text reveal**](https://www.recharm.com/effects/brush-stroke-text-reveal) - [Burning text **Burning text**](https://www.recharm.com/effects/burning-text) - [Drop shadow text **Drop shadow text**](https://www.recharm.com/effects/drop-shadow-text) - [Echo text **Echo text**](https://www.recharm.com/effects/echo-text) ## Find 3x _winning ads_ Recharm cuts your ad footage into tagged, searchable clips: hooks, testimonials, product shots. Find the shots that win, add the effect with Claude, and ship 3x more ad edits. [Start 14-day free trial](https://www.recharm.com/get-started)