How to Create Character-by-Character PDF Form Fields Using Acrobat Comb
Question details
The user wants to format a PDF text field so that each typed character automatically aligns into individual preprinted boxes on a scanned form.
- Product
- Adobe Acrobat
- Device & OS
- not provided
- Scenario
- Digitizing a printed or scanned form where specific inputs (like SSN, account numbers, or names) require exactly one character per printed box.
- Observed behavior
- Instead of manually creating dozens of individual text boxes for each character, the user is looking for an automated way to split a single text entry into equally spaced character boxes, while forcing the input into uppercase letters.
Ensure you have access to a PDF editor with advanced form creation capabilities, such as Adobe Acrobat Pro or Standard, since free document readers do not support modifying form field properties.
Use the Comb Property in Acrobat Text Fields
Enable the built-in Comb property to automatically divide a single text field into uniform, equally spaced boxes based on a specified character limit.
The Comb property is an advanced text field feature designed specifically for scanned forms with preprinted grids. When activated, it restricts the user's entry to a set number of characters and physically spaces them out to fill the entire width of the text field.
Open your document in Acrobat's 'Prepare Form' mode. Draw one large text field that spans across the entire group of preprinted boxes where the text should go.
Right-click the newly created text field and select 'Properties' from the context menu to open the Text Field Properties dialog box.
Navigate to the 'Options' tab. Check the box labeled 'Comb of' and enter the exact maximum number of characters (which corresponds to the number of preprinted boxes on your form).
To force all entered letters to become uppercase automatically, go to the 'Validate' tab. Select 'Run custom validation script', click 'Edit', and paste the following code: event.value = event.value.toUpperCase();
Click 'Close' to exit the properties window, then switch to 'Preview' mode to test typing in the field. The letters should space out automatically and convert to uppercase.
Create, Edit, and Fill PDF Forms with WPS Office
If you frequently work with scanned forms, WPS Office provides a robust set of PDF editing tools. It allows you to quickly add text, checkmarks, and custom fields to digitized documents without a steep learning curve.
- 1. Open your PDF in WPS: Launch WPS Office and open your scanned document or existing PDF form.
- 2. Access the Form tools: Navigate to the 'Form' tab on the top ribbon to access the interactive field creation tools.
- 3. Add Text Fields: Click 'Text Field' and drag across your document to place fillable areas exactly where you need them.
- 4. Fill and align text: Use the alignment options to perfectly position text over printed boxes, then save your finalized document.
Frequently Asked Questions
Why is the Comb option grayed out in Acrobat?
The Comb property conflicts with certain other text formatting settings. To make it selectable, ensure that 'Multi-line', 'Password', 'File Selection', and 'Scroll long text' are all unchecked in the Options tab.
How do I fix the character spacing if it doesn't align with my boxes?
The Comb option automatically calculates spacing by dividing the total width of your text field by the number of characters. If the letters don't align perfectly with the printed boxes, use the selection tool to resize the overall width of the text field until the alignment matches.
Will the uppercase JavaScript validation work on mobile devices?
Custom JavaScript validations rely on the PDF viewer's scripting engine. While this works perfectly in desktop versions of Acrobat and robust desktop editors, many lightweight or mobile PDF readers do not support JavaScript, meaning the text might not automatically convert to uppercase on those devices.
