When printing onto the blue paper, the images appeared "scaly" and after transferring, large planes appeared pitted. This was made even worse when we tried our cheap chinese press-n-peel alternative - it was practically unusable (our first pcbs did actually etch into working boards, but it would only be a matter of time before we started getting impossible-to-debug hairline cracks in traces).
However, we weren't quite ready to give up on our chinese press-n-peel alternative just yet.
The blue original paper is about £21 for just five sheets. After postage costs, that's nearly a fiver a sheet!
The cheap chinese stuff we got cost us ten pounds for a hundred sheets, delivered to the door. That's 10p a sheet. A hundred sheets of blue press-n-peel would be in the region of £450!
After doing a bit of digging around online, we found a few forums in which readers said that they too had problems with press-n-peel and the Brother desktop laser printers. It's all to do with the propriety toner they say.
Now we already know that Xerox toner works really well. It's something to do with the high plastic content in their toner, apparently. But which other printers are recommended for toner transfer etching?
- Xerox Phaser printers give great results
- Oki-based printers are the same as Xerox (one is just a re-badged version of the other!)
- From experience, we know that HP Laserjets give a decent result
- A lot of people have had success with Dell lasers.
As it happens, a seller local to Nerd Towers was selling a Dell laser printer (an unwanted office raffle prize) for £20. For less than the cost of replenishing our blue press-n-peel, we could get hold of a different laser printer to try with our chinese clone paper.
Even if the chinese paper still turns out to be no good, we're not really very happy with the Brother desktop laser printer, so it seemed like a twenty-quid punt; even if we had to stick to blue paper in the future, the Dell surely had to give better results than the nasty Brother printer - didn't it?
A few hours later, we had our Brother printer on Freecycle, and a new Dell printer installed.
Already the black print on the cheap chinese paper looked better than the results we were getting with the Brother printer. Things were looking promising....
On the press-n-peel blue, however, the black toner still appeared quite "scaly", just like the Brother. Perhaps not so promising after all!
The yellow image transferred onto the copper pretty well.
It's not 100% perfect, and there are still a few little areas where you can see the image is slightly broken - around large planes - but all the tracks and pads transferred as solid shapes and look good. This transfer looks better than the images we were getting with genuine press-n-peel blue and our Brother printer.
The press-n-peel blue paper gave even better results
Nice solid lines, good definition on the pads, and large planes completely covered in toner. The best transfer we've had since the days of the Xerox printer!
And for the final test - etching.
The cheap chinese paper actually performed pretty well. There's still a bit of pitting around the large planes, but the traces and pads all came our really nicely. There's probably no problem with colouring over the large planar areas with a sharpie pen before etching on the next board.
In comparison terms, we felt that this was actually a better etched result than we got with our Brother printer and the genuine press-n-peel blue paper.
And to complete the test, here's a board etched using press-n-peel blue and the new Dell printer.
An almost perfect etch. Pads and traces and sharply defined, and large planes are complete and full, with very little sign of pitting. There's no doubt that press-n-peel blue gives a superior result. But our cheap chinese alternative paper is actually pretty usable too, when used with the right printer!
So there we have it.
Toner transfer is highly dependent on the type of toner in your printer (and by extension, since most people stick to the toner provided by their printer manufacturer, the make of your printer).
We've never had success with using magazine paper or cheap photo paper, but others swear by it, because it's a much cheaper alternative to press-n-peel blue. Maybe they're just using laser printers that happen to work well with the type of paper that they're using. Because we've just found that not only does the paper make a difference to the transfer, but the type of toner being used has a massive impact on it too.
So it's quite possible that you can use cheaper alternatives to press-n-peel blue toner transfer paper; you just need to make sure you use a suitable printer with it too.
In our experience (from the limited number of different printers we've actually tried) we rate laser printers in the following order, for toner transfer:
- Xerox/Oki - the best results by a long shot
- HP Laserjet - very good results requiring little or no touching up before etching
- Dell - very good results, a little touching up required on large areas
- Brother - don't even bother; useable only with expensive blue paper and lots of touching up still required before etching
For now, we're pretty happy with our Dell laser printer.
And with a stack of 99 sheets of cheap chinese press-n-peel alternative, it'll be a long time before we hope to repeat this kind of experiment - there's enough paper there to keep us going for a long time!