Washing a document is a dramatic and potentially dangerous procedure. Aside from the potential of running inks, wet paper is very fragile and easily torn. Any small mistake could do irreparable damage to the letter, and a piece of history would be forever lost. Only trained conservators should do this kind of treatment.

Before immersing the document, we will test the inks and pencil one final time for solubility with the actual water that will be used for the bath.

Now we can begin to introduce moisture into the document. We cannot simply drop the letter into a tray of water. Rather, we want to maintain as much control as possible to ensure the letter's safety. To do this, we will put the letter on a blotter and spray it with a gentle mist of water from the bath. This lets us control the process and make sure the letter gets wet slowly and evenly to prevent staining.

After the first side is sprayed out, we will place another blotter on top of it, so that the letter is sandwiched between blotters. These will provide support for the letter as we turn it over, because as it gets wet, the letter becomes prone to tearing under its own weight. We will continue spraying the document and turning it over between blotters until it is completely wet out.

When the document is finally wet, we put a sheet of polyester web on top of it, and turn it between blotters one last time. This sheet of polyester web can support the wet paper while it is in the bath. Now it is time to pick up the polyester web and use it to transport the letter into the tray of water.

Once the document is floating on the surface of the bath, we gently press it below the surface of the water. While the document is getting wet, we cannot take our eyes off it for a moment, because we must always watch for any change to the ink. Despite our careful testing, ink sometimes does run unexpectedly, and the letter must be immediately removed from the water if that happens. Now we can soak the letter for a minute or two, while the adhesive that is holding on the silk and tape softens.

Most conservators will tell you that their favorite tool is a shaped piece of bone called a "bone folder." These bone folders are useful for everything from neatly creasing cardboard to make a folder to smoothing out wrinkles in a letter. We will use a very thin bone folder to lift the silk and tape away from Houston's letter. Because the bone is so thin and sharp on the end, it can easily stab into the fragile wet paper. Therefore, we have to be extremely cautious when using it. The bone folder is inserted under the silk and used to carefully lift the silk away from the document. Making sure that all of the silk and tape are removed from the document is a time consuming process, because the adhesive softens slowly in water and cannot be rushed.

After the silk and tape are off, we need to remove any adhesive residue remaining on the surface of the letter so that it cannot get sticky if the letter gets wet in the future. We do this by running a very soft brush over the surface in all directions. We use almost no pressure when doing this. Rather, the gentle brushing removes adhesive residue that is already almost completely detached from the document. Again, we have to be extremely cautious when using a tool so that we don't damage the fragile paper.

Now that the tape, silk, and adhesive are completely off the surface of the letter, we can add the calcium buffer to neutralize acids released by the paper as it deteriorates. While this step will have no visual effect on the document, it is one of the most critical steps for prolonging the letter's life. We will fill another tray with water and add a saturated solution of calcium hydroxide to it, until we have raised the bath's pH to about 8.5. We can measure the pH with test strips that react to the amount of alkaline material in the water. We carefully lift the letter out of the first bath on its polyester support, using great care not to tear or distort it. Then we lay it into the alkalinization bath where it soaks for several minutes.

Once the alkalinization bath is complete, we are ready to begin the drying process. Drying a wet document completely is critical, because any dampness left in the letter can cause mold growth which can destroy a document. We remove the document from the bath and place it on a blotter. Then we put another blotter on top of the letter. Once the letter is sandwiched between blotters, we smooth them with our hands, using almost no pressure that could distort the letter to encourage the blotters to soak up as much moisture as possible.

Now we turn the letter over, using the blotters to support it, and remove the top blotter. The polyester web is sitting on top of the letter. We have to remove it, which is a tricky process because the wet paper tends to want to stick to the polyester web. If it sticks, it can cause the letter to distort, or worse, to tear. Getting very close to the letter so that we can monitor exactly how it reacts to having the web removed, we carefully and slowly roll the polyester web back.

Now we place another blotter on top of the letter, and smooth the blotter sandwich again. The process of turning and replacing blotters repeats until the letter feels dry and cool to the touch. However, just because the document feels dry, doesn't mean that it is. There is still residual extra water that must evaporate before the letter is completely dry and poses no risk of mold growth. This process can take several hours.

Therefore, we let the document finish drying between press boards and under the weight of a lithography stone. The extra weight of the boards and the stone encourages the letter to dry flat, instead of distorting as the water evaporates at uneven rates over its surface.

Once completely dry, the letter shows a marked improvement in color, legibility, and flexibility. Now all that remains is to mend the tears.