Read only RTF format?

My users print receipts with dot matrix printer, therefore we used RTF format to print (pdf very slow with dot matrix). However, users seems to be able to change the receipts before printing. To prevent that to happen, I need to generate the READ ONLY receipt so that they can’t save/edit before printing.

Is there a way to do that?

Please advise. Thank You.

No, you cannot make a text file which they can print but can’t alter. It’s not possible no matter what format you use. They could edit the PDFs before printing if they wanted as well. Even if you locked down the file so they could do nothing but see it, they could take a screenshot, edit the image and print that. The most you can do is make it more difficult, such as perhaps rendering the receipt as an image instead of text?

for pdf we can make it as read only right?

rendered the receipt as image, sounds good! But will it be slow to print an image with dot matrix?

I don’t know, never owned one. But a read only PDF isn’t uneditable either. You basically just make your changes on top of the existing document then print that.

Maybe you can generate a transaction number on the receipt. Then, anyone who might need to trust the data on the receipt, can verify it by using some web based tool you provide.

hmm but at least it’s not as easy as the RTF format where they can just change everything they want before printing it out, right?

True. But RTF has no DRM-like features like a PDF has. It’s a plain text format, so as long as you’re using RTF it’s easily editable in a text editor.

we do provide the transaction number on the receipt, but somehow they requested for “uneditable” or “not able to save” format for the receipt.

hmm, so i guess it’s either pdf (at least not so easy to let them edit) or image?

no other options?

You should explain to them why it’s a bad idea to assume a user cannot forge a receipt.

ya we did, but according to them, they just want something where the user not able to edit anything at the first glance. At least not as easy as RTF where they can change immediately/easily.

You could create your own software to print the receipts, and provide the receipts in a proprietary format you invent that only your software knows how to read. This is how some store chains do printable coupons over the internet – the end user has to download a program that prints the coupons, preventing them from easily making many copies or editing them.