Paperform doesn't provide tools to modify the width of your embedded form.

An alternative to in-built tools is to apply some CSS rules within the page your form pop-up appears on. Providing the pop-up container less available space may work to reduce the width of the overall form, although this isn't guaranteed.

Example CSS

The following example restricts the pop-up form container to a width of 400px. The example CSS rule should be added to the stylesheet for the page your form is embedded on.

.Paperform__popupcontent {
    max-width: 400px;
}