Products
3 min to readLast update on 11 September 2026

How to Set Up Product Sizes?

Custy Product Size options let you offer several sizes and charge a little more for bigger ones if you want. Shoppers pick sizes in the Design Lab when they add the design to the cart.

You can build size lists once and reuse them on many products. Changing a size set does not delete your Shopify products.

Two places to work with sizes

You will use sizes in two spots. Both use the same size lists.

  1. 1ProductsProduct Size tab: build and edit shared size sets for the whole store
  2. 2Customize ProductProduct Sizes: pick which size set this one product uses

Step 1: Open the Product Size tab

In Custy, click Products on the left. At the top, click the Product Size tab. This is where you manage shared size sets.

Products page with Product Size tab and size set listFull size
Open Product Size to build size lists you can reuse.
  1. 1

    Product Size

    Top tab for shared size catalogs (next to Create Colors and Printing Types).

  2. 2

    Category tabs

    Open Sizes, Adult Sizes, and Youth Sizes. Pick the group that matches the product.

  3. 3

    Add Size Set

    Create a new size list for the category you selected.

  4. 4

    Size set list

    Each row shows the set name, sizes, and whether products already use it.

Step 2: Pick a size category

Custy gives you three categories. They work the same way: each holds size sets with named sizes (S, M, L, and so on).

  1. 1Adult Sizes: for adult apparel and most everyday products
  2. 2Youth Sizes: for kids and youth products
  3. 3Open Sizes: another labeled group for size lists (same setup as Adult and Youth)

Good to know

Shoppers do not type free-form measurements here. They pick from the size titles you add. If a product has no size set, the Design Lab may show a simple quantity step instead.

Step 3: Create a new size set

On the Product Size tab, pick a category, then click Add Size Set. The Create Size Set window opens.

  • Enter a Size Set Name (for example Adult Tee or Mug One Size).
  • For each size, fill in Size Title (S, M, L, XL) and optional Extra Price ($).
  • Click Add Size for more rows.
  • Drag the handle to reorder sizes. Use the trash icon to remove a size.
  • Click Save.
Create Size Set modal with name, size titles, and extra pricesFull size
Name the set, add sizes and optional extra prices, then click Save.
  1. 1

    Size Set Name

    A clear name you will recognize when assigning this set to products.

  2. 2

    Size Title

    What shoppers see (for example S, M, L, or 2XL).

  3. 3

    Extra Price ($)

    Optional add-on for that size. Use 0.00 if there is no extra charge.

  4. 4

    Add Size

    Add another size row to the list.

  5. 5

    Save

    Creates the size set. On edit, this button says Update.

Step 4: Edit, copy, or delete a size set

On the Product Size list, use the row actions:

  • Edit: open Edit Size Set, change names or prices, then click Update.
  • Duplicate (copy icon): makes {name} (Copy) so you can tweak a new list without changing the original.
  • Delete: only when the set is Not used. If products already use it, remove it from those products first.
Size set table with Edit, duplicate, and Delete actionsFull size
Edit or copy a set anytime. Delete only when no product is using it.
  1. 1

    Status

    Shows how many products use this set, or Not used.

  2. 2

    Edit

    Change the set name, sizes, or extra prices.

  3. 3

    Delete

    Available when the set is not assigned to any product.

Step 5: Assign a size set on Customize Product

Open the product (Make it customizable or Edit). Scroll to Product Sizes.

  • Choose Adult Sizes, Youth Sizes, or Open Sizes.
  • Open the Size Set dropdown and pick a set (or leave No Size Set).
  • Optional: click Edit Set to change the selected set, or + New Size Set to create one here.
  • Check the size badges under the dropdown. Custy saves the choice as you go.

After you assign sizes

Finish the rest of Customize Product if needed, set Active on designer to Yes, and click Save. Shoppers then pick these sizes in the Design Lab.

Customize Product Product Sizes section with Size Set dropdownFull size
Pick a Size Set for this product. Shoppers only see the sizes you enable here.
  1. 1

    Size Set

    Choose an existing size list for this product.

  2. 2

    Edit Set

    Change the sizes inside the selected set.

  3. 3

    + New Size Set

    Create a new size list and use it on this product.

What to do next

Next, add extra prices on sizes if you need them, then set up product colors.