Episode thumbnail rail

Published by GTM Vault (gtmvault.co) as part of How GTM Vault Is Run. Swap the show names, links and templates for your own.

Every new episode ships two key images, built in Canva from the show's existing set, never from scratch:

1. YouTube thumbnail. A cold-feed object competing against unrelated videos. Leads with a claim.
2. Substack card. A catalogue object sitting in a grid next to its siblings. Leads with the guest and the series.

They differ on purpose. Never unify them, and never flag the mismatch as a problem.

Coffee Walk is the exception. Its format uses one image for both surfaces. The rail builds that one image and says so. It does not invent a second layout.

The visual rules for each layout are owned by gtm-vault-episode-format (Thumbnails section). Read that section at the start of every run. This rail owns the procedure and the Canva mechanics. If the two disagree on a visual rule, episode-format wins; tell the host about the conflict.

Pair with gtm-vault-writing for headline copy and gtm-vault-positioning for any claim or number.

Approval gates

1. Build every new page in a working copy, never directly in a master set design. The master set changes only after the host approves the export in chat.
2. Never publish to YouTube or Substack. The rail delivers PNGs and a page in Canva; the host uploads.
3. If a guest photo, still or logo is missing, stop on that image and say which asset is missing. Never substitute a stock photo, a generated face or another guest's photo.

The Canva sets

Each show has one master design per surface, one page per episode. Record the design IDs in the table below when you set the rail up. A Canva design ID is the string in the editor URL after /design/ (for example canva.com/design/<ID>/edit).

Titles lie. Duplicated masters often end up named "Copy of ..." while the originals with the clean names go stale. Always confirm the master by reading its pages and finding the highest episode number, not by its title.

Show	Surface	Master design	Page order
Podcast	YouTube	<your Canva template design ID>	Page 1 is the channel cover; page 2 is newest
Podcast	Substack	<your Canva template design ID>	Page 1 is newest
SMYS	YouTube	<your Canva template design ID>	Set when the template exists (see Open gaps)
SMYS	Substack	<your Canva template design ID>	Page 1 is SMYS 1; last page is newest
Coffee Walk	Both	<your Canva template design ID>	Page 1 is Coffee Walk 1

Keep a short list of stale designs next to the table (older forks, designer drafts) so the rail never builds from them.

If a master's latest page is more than one episode behind the episode being built, stop and ask whether a newer master exists. That is the signal the set has been forked again.

Inputs per episode

Collect these before touching Canva. Pull from the episode write-up and the pipeline first; ask the host only for what is missing.

1. Show and episode number.
2. Guest full name, written per the diacritics rule (plain Latin letters, no diacritics, in every name and place).
3. Guest title and company, plus company logo for the podcast YouTube layout.
4. Headline claim for the YouTube thumbnail. Source it from the episode's YouTube title hook, not the Substack title. Two halves: the setup (white) and the asset (gold). Mark any displaced word for a coral strike or coral annotation.
5. SMYS only: the stack, in the order the guest uses it, and the two tools for the tool-to-tool headline.
6. Guest photo (podcast: cut-out; SMYS card: head-and-shoulders, no other company's logo on clothing). Coffee Walk: the location still from the cut.

Procedure

Report progress to the host after each image, not at the end.

Step 1. Read the format and confirm the masters

1. Read the Thumbnails section of gtm-vault-episode-format.
2. Load the Canva tools with tool_search (read-design, copy-design, edit-design and the editing transaction tools, merge-designs, create-upload-url, remove-background, get-export-formats, export-design).
3. Read each master needed for this show and confirm the latest episode on file. Note the page number of the most recent episode page: that page is the template, because it carries the current fonts, sizes and badge treatment.

Step 2. Make the working copy

For each image, copy-design the master with only the latest episode page. This gives a one-page working design that inherits the exact fonts and layout. Title it [Show] [N] [Surface] WIP, for example GTM 53 YouTube WIP.

Work by replacing text in existing elements, never by adding new text elements. The Canva API cannot assign a font family, so new text falls back to the label font. Replacing text inside an existing element keeps its styling.

Step 3. Fill the layout

Podcast, YouTube (guest-face layout).

1. Headline in Title Case, two or three lines, setup in white and asset in gold.
2. Guest title line, company logo, episode number in the bottom-left badge.
3. Strike-through, if any, is coral, never white.
4. Swap the guest cut-out: upload the photo with create-upload-url, run remove-background if it is not already cut out, then replace the image element.

Podcast, Substack (gradient-and-guest card).

1. Guest full name in white caps lower-left; company and episode as "COMPANY · GTM N" if the template carries that line.
2. Gradient colour rotates (red, mint, tan, blue, purple). Read the thumbnail of the previous episode's page and pick a colour that does not match it.
3. Swap the guest cut-out as above.

SMYS, YouTube (tool-to-tool layout). Blocked until a template exists. See Open gaps.

SMYS, Substack (guest-on-black card).

1. Guest full name lower-left over two lines in white.
2. Gold line "COMPANY · SMYS N", company dropped if the guest is independent.
3. Stack strip along the bottom in grey, tools separated by spaced middle dots.
4. Guest photo cropped head-and-shoulders, face on the right third.

Coffee Walk (split-panel, one image). Change exactly five things: the two headline lines (setup, then turn, never a length split), the name, the role line, the badge number. The location still goes in the right panel. Image placement through the API needs an uploaded asset; if the host has not supplied the still as a file, leave the old still in place and say it is the one manual step.

Step 4. Check before export

Run every check on every image. Fix and re-check rather than shipping with a note.

1. Thumbnail at 210px wide: headline readable, strike visible, nothing smudged.
2. Gold sits on the asset half of the claim; coral only marks what is dying or displaced.
3. No em dashes, no emojis, no exclamation marks, no diacritics in any name or place.
4. Episode number matches on badge, card line and file name.
5. Fonts match the previous page. If any text renders in the fallback label face, say which element; it needs setting once in the editor.
6. Nothing from the previous guest survives (name, logo, company, stack, photo).

Step 5. Export and deliver

1. get-export-formats, then export each working design as PNG, 1280x720.
2. Hand the host the PNGs as files in the same message, named GTM-53-YouTube.png, GTM-53-Substack.png, SMYS-10-YouTube.png, CW-2-Thumbnail.png.
3. Give the Canva edit link for each working copy.
4. List any manual step left (photo drop, font set) per image. An image with a manual step outstanding is reported as not done.

Step 6. File into the master set (after the host approves)

Once the host approves, insert the page into its master with merge-designs at the position that matches the set's order: page 2 for podcast YouTube (after the cover), page 1 for podcast Substack, last for SMYS Substack, next page for Coffee Walk. Read the master back and confirm the page count rose by one and the new page sits where expected.

Remind the host of the Substack step the API cannot do: the social preview card is set by hand in File Settings.

Report in chat

One message, numbered: which images are done with file names, which are blocked and why, manual steps left, and the Canva links. No recap of the steps.

Open gaps

Keep this section current so the rail knows what it cannot build yet.

1. SMYS YouTube thumbnail template. The tool-to-tool layout is documented in episode-format. Until a Canva design for it exists and its ID is recorded in the table above, the rail builds the SMYS Substack card only and reports the YouTube image as blocked.
2. Coffee Walk ships one image, not two. Per format. If a separate Substack card for Coffee Walk is wanted, that is a format change: update episode-format first, then add a master here.