Choose the job before choosing the extension
A prepared signature asset and a signed document are different deliverables. The asset holds the handwriting or stamp for placement on future pages. The completed PDF holds the document and the visible mark together. Sending the isolated signature when somebody asked for a completed form leaves them with the wrong file, even if the image looks excellent.
Keep a prepared master in the library and export copies for specific destinations. For example, use “signature-original.png” as a reusable image and “application-signed-copy.pdf” as the reviewed document output. The format is only one setting: an image may also need a transparent or opaque background, a quality choice, and an appropriate size.
Compare the practical choices
PNG is lossless and supports alpha transparency. WebP supports lossless and lossy modes with alpha transparency. Ordinary JPG output in Paperkiss is opaque and uses a selected background. These capabilities do not mean that every file with a particular extension uses every available feature. Check the export settings and the receiving workflow.
For a thin signature, begin with a lossless transparent asset and inspect its strokes after reopening. If you choose a lossy export, compare that particular result with the master at its intended size. There is no universal file-size saving that can be promised for every stamp or photograph. Test the actual file rather than choosing a format solely from a general compression claim.
| Format | Reusable transparent asset | Typical role in this workflow |
|---|---|---|
| PNG | Yes, when exported with transparency | Default prepared signature or stamp |
| JPG | No in Paperkiss export | Deliberately opaque page or image |
| WebP | Yes, with a supported destination | Alternative asset with a chosen lossless or lossy mode |
| Document output | Completed document with placed artwork |
Use PNG as the reusable starting point
PNG is the straightforward default when you need to see the page through the empty areas around the mark. In the developing Paperkiss export workflow, select PNG and choose a transparent background explicitly. A PNG exported on white can still create a white box when placed on a shaded form.
Keep the prepared image large enough for your intended placement, but do not expect enlargement to restore detail missing from the source. Reopen the export over both light and dark surfaces. If you need to revise the mask or colour later, return to the saved master and export a fresh copy; do not repeatedly edit a small derivative that no longer represents the original preparation.
Use WebP or JPG for a specific destination
WebP is an option for reusable transparent artwork when the destination accepts it. Paperkiss includes a lossless option and a quality control for lossy WebP in its implemented export dialog. Try the exact exported file in the receiving application before committing to that delivery format; support for a file type can differ between applications and import paths.
Choose JPG when you deliberately need an opaque image, such as a finished image of a page on white. Select the background so transparent areas do not receive an unintended colour. Keep a transparent PNG master as well if the signature will be reused. Renaming a JPG to PNG or WebP changes no pixels and does not create transparency.
Keep PDF as the completed-document output
For an existing PDF, export a new PDF copy after placing and reviewing the mark. The Paperkiss implementation adds artwork while retaining the original PDF content; newly inserted handwriting remains visible image artwork. Exporting pages as PNG, JPG, or WebP instead creates page images, which is a different deliverable and can produce one file per selected page.
Paperkiss is still in development and supports PDF, JPG, PNG, and WebP as its defined input/output scope. Before sharing anything, reopen the actual output and confirm its page count, background, signature position, and format. Keep the original document, library master, and any editable draft separately. A collection of page images should not be mistaken for a single multipage PDF.
Questions and answers
Is WebP always smaller than PNG?
Do not assume that for your asset. Compare actual exports at the quality you need. Transparent edges and readability matter more than an unverified percentage saving.
Can a PNG contain a white rectangle?
Yes. PNG supports transparency but does not require it. A white background may be stored as opaque pixels or chosen during export.
Does PDF replace my reusable signature master?
No. Keep the prepared library item or a transparent image for reuse. A completed PDF is the document output, while a draft is the editable local project.