Start again from the unsigned copy
If a signature lands on the wrong page or covers text, return to the unsigned PDF and check the physical page order before creating a replacement. Adding another signature to the faulty download does not remove the first image.
Keep the original and the unsuccessful output separate. Identify the exact form version you need to return, then open its thumbnails in a PDF viewer. Count from the first PDF page, including covers and instructions. A printed label such as “Page 4” can belong to the fifth page in the file.
The ToolboxHub Sign PDF tool takes a whole page number starting at one. It has three positions: Bottom right, Bottom left, and Center. It does not show the PDF beneath the drawing canvas, so the canvas is not a preview of where the signature will land. If the form requires precise placement inside a narrow field, use an editor that lets you inspect and position the signature on the page.
Work through a six-page approval form
For example, imagine an unsigned six-page internal approval form with a cover first, four form pages next, and an attachment last. The signature area is on the fifth physical page, although the printed footer says “4.” This is an illustrative form, not a document tested in a browser during this review.
Use a disposable form with a visibly empty lower-right area for a first placement check. Choose that PDF, draw a fictional mark such as a zigzag, enter 5 in Page to sign, leave Position at Bottom right, and select Place signature. The expected download name is signed.pdf; your browser may adjust the name if another download already uses it.
The intended result is still six pages, with the added mark on physical page five and none added to the other pages. Reopen the downloaded file and check all six thumbnails, then examine page five at normal reading size and at a closer zoom. Confirm that the mark is readable and does not hide a label, date, instruction, or part of the form border. Do not judge success only by whether a file downloaded.
To reproduce the page-number check, repeat from the same unsigned sample with page 1. The new mark should appear on the cover instead. Keep the two outputs distinguishable while comparing them. This control tells you whether you were selecting the physical page you intended; it does not establish that the real form accepts image signatures.
Decide whether any preset can fit
A preset can work only when its fixed image area falls in usable space. Changing the selected page does not change that placement rule.
The current component embeds the whole drawing canvas at 180 by 52 PDF points. Bottom placements start 56 points above the page bottom, with a 48-point side margin; Center uses the middle of the page. On a simple unrotated page measuring 612 by 792 points, the lower-right image box therefore runs from x = 384 to 564 and y = 56 to 108. Those coordinates are an arithmetic illustration of the inspected implementation, not a rendering measurement from an actual signed file.
Blank margins inside the canvas are included in that box. A tiny mark in its corner remains tiny after placement. Clear signature and redraw using more of the canvas if legibility is the problem, but this will not move the overall box onto a different signature line. There is no drag handle, size slider, or automatic search for a signature field.
The library's official PDFPage.drawImage documentation describes drawing an embedded image with position and size options. ToolboxHub supplies fixed values for those options; it does not expose the library's full range of editing controls. This review checked the component code and that API documentation on September 27, 2026, without running a PDF rendering test.
Match the symptom to the next action
If Place signature is disabled, check both prerequisites: a file must be chosen and the canvas must contain a mark. Clearing the canvas disables placement again until you draw. Choosing a PDF alone is insufficient.
If a page-number error appears, count the file's physical pages again and use an integer between one and that count. In the six-page example, 0, 7, and 5.5 are not valid page selections. Do not substitute the printed footer number without checking the thumbnails.
If handwriting covers text, stop trying the same preset on successive downloaded copies. Return to the original, inspect whether another preset actually has enough empty space, and change editors if none fits. An embedded image cannot be erased with Clear signature: that button clears the drawing canvas only.
If placement looks unexpectedly clipped or displaced, inspect the page dimensions and whether the page is rotated or cropped. The component has no crop-aware placement preview. A small or unusual page needs visual verification, and a fixed box may be unsuitable even if the PDF loads successfully.
If processing fails before a download, first confirm that the unsigned PDF opens normally elsewhere. The tool loads pdf-lib from an external CDN, so a blocked library request can also prevent processing. It has no password-entry interface; obtain an appropriate usable copy through the document owner's process instead of treating every load failure as a page-number problem.
Verify the actual attachment before returning it
Open the exact file you intend to attach, not a similarly named earlier attempt. Check the page count, target page, legibility, nearby text, and final filename. Preserve the unsigned original so you can reproduce the correction without accumulating marks.
The tool creates a new PDF containing handwriting as an image. It does not authenticate the signer, add a signing certificate, or determine a recipient's acceptance requirements. Check the recipient's official source for submission instructions before returning a document that requires a specific signing process. A visually correct position alone cannot satisfy such a requirement.
Frequently asked questions
Does the printed page number control placement?
No. Use the page's position in the PDF file, counting the first page as one. Covers can shift that position relative to printed numbering.
Can I drag the signature onto a line?
No. This tool offers only the three presets. Use an editor with on-page positioning when none lands in the required space.
Does Clear signature remove a mark from a downloaded PDF?
No. It clears the canvas for the next drawing. Start from the unsigned original to create a replacement without the previous mark.
Can I sign every page in one action?
No. Each placement targets one selected page. For a document requiring a coordinated multi-page signing workflow, use the recipient's specified process and verify its completed output.