How to make previews and thumbnails for teaching resources
A teacher decides in a few seconds whether to open your listing. Your thumbnail gets the click and your previews answer the question "is this what I need?".
Short answer: To make previews for teaching resources, export three to six real pages of your resource as PNG or JPEG images, plus one square thumbnail that shows the cover or the strongest page with a short title. Use honest images of the actual file, readable text and clear file names that match your resource. Previews and thumbnails are required for every resource.
What is the difference between a thumbnail and a preview?
The thumbnail is the single small image a buyer sees in search results and collection grids. Its only job is to make a teacher stop scrolling and recognize the topic, grade and type at a glance.
Preview images are the larger pictures on the product page. They show what is actually inside: a worksheet page, a slide, the answer key, a task card sheet. A teacher uses them to check level, layout and quality before buying.
With TeachLessons, previews and thumbnails as PNG or JPEG files are required for every resource you send. We may also make further previews from your files for the product page.
How should I design a thumbnail for a teaching resource?
Square thumbnails work best because they crop cleanly in grids on phones and desktops. A good size to aim for is around 1,000 to 2,000 pixels on each side, which stays sharp without making the file huge.
- Short title in large type. "Fractions Practice" reads at thumbnail size. A full sentence does not.
- Grade or level. "Grades 5-6", "Year 4" or "KS3" tells the teacher straight away whether it fits.
- Type of resource. Worksheets, task cards, slides, unit plan.
- One real page, shown clearly. A slightly tilted page or two overlapping pages works well. Avoid busy collages of ten pages.
- Contrast. Dark text on a light background, or the reverse. Check it at the size of a postage stamp.
Keep a consistent look across your thumbnails: same fonts, same layout, same color band for your subject. Buyers start to recognize your work, and your author page looks tidy.
Which pages should I show in my preview images?
Show the pages a teacher would want to check if they were holding the file. From experience, three to six previews cover most resources:
| Resource type | Good preview pages |
|---|---|
| Worksheet pack | Cover, two typical worksheets, answer key page |
| Task cards | One full sheet of cards, the recording sheet, the answer key |
| Slide deck | Title slide, a teaching slide, an activity slide, a slide grid overview |
| Unit or lesson plan | Overview page, one full lesson, an assessment page |
| Game or activity | Game board or cards, the rules page, a photo-style mock-up if you have one |
If a resource is long, a page grid (nine small pages on one image) shows the range. Follow it with full-size pages so teachers can read the questions and judge the level.
How do I keep previews honest and still protect my work?
Previews should show the resource exactly as the buyer will get it. Don't show pages that aren't included, and don't use mock-ups of laminated cards if the file is a plain PDF without saying so. Mismatched expectations lead to disappointed buyers and refunds, and a refunded sale is not paid out.
To protect your work, you don't need to blur everything. Simple options:
- Show answer keys at a smaller size, or crop to the first few answers.
- Add a light "Preview" label across a corner.
- Show a representative sample, not every page.
The text on preview pages should still be readable. A teacher who can't read the questions can't judge the level, and will usually move on.
What tools can I use to make previews?
You don't need special software. Most teacher-authors use the tool they built the resource in:
- PowerPoint or Keynote: set the slide size to square for the thumbnail, then export slides as PNG or JPEG images.
- Google Slides: download a slide as a PNG or JPEG image from the File menu.
- Canva and similar design tools: use a square design for the thumbnail and download as PNG or JPEG.
- PDF files: many PDF readers can export pages as images, or you can take a clean screenshot at full zoom.
Whatever you use, check the final images at full size for blurry text, cut-off edges and leftover placeholder text. If your thumbnail uses clip art or fonts, the same commercial license rules apply as in the resource itself. See clip art and fonts for commercial use.
What are the most common preview mistakes?
Looking at a lot of listings, the same problems come up again and again. Most are quick to fix before you send anything:
- Text too small to read. A full A4 or US Letter page shrunk into a thumbnail turns into gray lines. Show part of a page at a larger size instead.
- Wrong grade on the image. The thumbnail says Grades 3-4 but the description says Grades 4-5. Pick one and use it everywhere.
- Old versions. Previews made from an earlier draft show pages that changed. Make previews last, from the final file.
- Too much decoration. Borders, stickers and five fonts hide the content teachers came to see.
- Missing answer key. If the resource includes one, show that it does. Many teachers check for it before buying.
Because resources go live as soon as they are set up, without an extra approval round, it pays to do this check yourself before you send.
How should I name preview and thumbnail files?
Clear names save time on both sides and stop images ending up on the wrong product. Use the resource file name as the base and add a suffix:
- Fractions-Practice-Grades-5-6.pdf
- Fractions-Practice-Grades-5-6-thumbnail.png
- Fractions-Practice-Grades-5-6-preview-1.png, -preview-2.png and so on
In the Resource Submission List you enter the preview and thumbnail file names in the row for each resource. If the names match, your listings are set up faster. Our guide on submitting many resources at once shows the full routine.
Frequently asked questions
Are previews and thumbnails required?
Yes. Every resource you send to TeachLessons needs previews and thumbnails as PNG or JPEG files.
What size should a thumbnail be?
Square thumbnails work best. Around 1,000 to 2,000 pixels per side stays sharp in grids without making the file very large.
How many preview images should I make?
Three to six usually cover a resource well: the cover, typical pages and the answer key or overview.
Can I use PDF files as previews?
Send previews and thumbnails as PNG or JPEG images. You can export PDF pages as images in many PDF readers.
Should I watermark my previews?
A light label is fine, but keep the text readable. Teachers need to read the questions to judge the level.
Will TeachLessons make extra previews?
We may make further previews from your files for the product page, in addition to the previews you send.
Ready to sell your teaching resources?
Apply with the short form. We email you the seller documents, you send your final files with previews and thumbnails, and we set up your product pages, your author page and landing pages. You keep 70% of net revenue, with no fees and no exclusivity.
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General information about the TeachLessons Seller Program, not legal, tax or financial advice. The signed Seller Agreement sets out the binding terms. Questions: support@stifo.de.