Upsize and up resolution - - possible?

Hi Brum,

In general, you can not expect a sharp line result if it's a bit map (raster) image. Vector images can be set to any size.
Think of the pixels as tiles. By simply upsampling, you still have only 32 x 30 tiles of information in an 8" x 10" image. Information is not added. An original tiles is simply replaced by multiple tiles which are almost identical in appearance.

However, I have found that for some images you can improve matters. It depends on the image. Occasionally, some of the following helps. But it's never the same as starting with an 8" x 10" image at 300 ppi.

Smooth first:
1. Upsample using FILE > FILE FORMAT PLUG-INS > IMPORT > PHOTOZOOM PRO 2. Supposedly, they are using "splines"to get interpolation from more tiles than the standard bicubic which only smooths by using 3 adjacent pixels in two dimensions. It will do very little for your example.
2. SELECT and then GAUSSIAN BLUR areas which do not need sharpness. It makes the lines look sharper by contrast. This may help a lot if followed by sharpening.

Sharpen
1. The internet is filled with algorithms which claim to sharpen. They don't seem to work any better than the ones I've tried in Photopaint but look them up anyhow.
2. The heavy hitter on sharpening is EFFECTS > SHARPEN > UNSHARP MASK. Look it up in HELP. Use it last since other techniques may wipe out its benefits.
3. Increase contrast in both tone and color. I prefer S Curves in all three Lab curves (L ,a, b). Again, contrast will give the appearance of greater sharpness.
4. Try out all the effects in EFFECTS > SHARPEN. Some photographers have had good luck with the MEDIAN filter.
5. Believe it or not, adding noise may help. It may mask the pixellation which is your primary problem.

As always, the best solution is to start with a fine grain image.

GOOD LUCK.

Phil
PS: Can you post the original image as a JPEG. Use maximum quality.
Just out of curiosity, I would like to give it a try.