I've been asking everywhere, even Shopify support and haven't gotten any good answers on how to show size charts on my product page. From all my research, it seems like most shops have them as image files but in the new theme I'm installing there's no way to add alt text to it. I can have alt text on all other images, just not the size charts the way the theme is configured. (Without custom programming.)
As an alternative, I did find that I can link the chart as a separate page in my shop. From the user's perspective, you expand the size chart area, see the link to the chart and click on it. This means you'll have to use the back button to go back to the product page, which also isn't ideal. But it will allow me to use both graphical image file charts with alt text, and formatted tables for tabular text charts. (Some products have image fiile charts, some have tabular data.)
Opinions, which is better from a usability perspective?